diff --git a/Classes/Domain/Model/FileReference.php b/Classes/Domain/Model/FileReference.php
index 631af0a..215651e 100644
--- a/Classes/Domain/Model/FileReference.php
+++ b/Classes/Domain/Model/FileReference.php
@@ -71,9 +71,8 @@ class FileReference extends \TYPO3\CMS\Extbase\Domain\Model\FileReference
      * Set File uid
      *
      * @param int $fileUid
-     * @return void
      */
-    public function setFileUid($fileUid)
+    public function setFileUid($fileUid): void
     {
         $this->uidLocal = $fileUid;
     }
@@ -92,9 +91,8 @@ public function getFileUid()
      * Set alternative
      *
      * @param string $alternative
-     * @return void
      */
-    public function setAlternative($alternative)
+    public function setAlternative($alternative): void
     {
         $this->alternative = $alternative;
     }
@@ -113,9 +111,8 @@ public function getAlternative()
      * Set description
      *
      * @param string $description
-     * @return void
      */
-    public function setDescription($description)
+    public function setDescription($description): void
     {
         $this->description = $description;
     }
@@ -134,9 +131,8 @@ public function getDescription()
      * Set link
      *
      * @param string $link
-     * @return void
      */
-    public function setLink($link)
+    public function setLink($link): void
     {
         $this->link = $link;
     }
@@ -156,9 +152,8 @@ public function getLink()
      * Set title
      *
      * @param string $title
-     * @return void
      */
-    public function setTitle($title)
+    public function setTitle($title): void
     {
         $this->title = $title;
     }
@@ -177,9 +172,8 @@ public function getTitle()
      * Set showinpreview
      *
      * @param bool $showinpreview
-     * @return void
      */
-    public function setShowinpreview($showinpreview)
+    public function setShowinpreview($showinpreview): void
     {
         $this->showinpreview = $showinpreview;
     }
@@ -194,18 +188,12 @@ public function getShowinpreview()
         return $this->showinpreview;
     }
 
-    /**
-     * @param \TYPO3\CMS\Core\Resource\ResourceInterface $originalResource
-     */
-    public function setOriginalResource(\TYPO3\CMS\Core\Resource\ResourceInterface $originalResource) {
+    public function setOriginalResource(\TYPO3\CMS\Core\Resource\ResourceInterface $originalResource): void {
         $this->originalResource = $originalResource;
         $this->originalFileIdentifier = (int)$originalResource->getOriginalFile()->getUid();
     }
 
-    /**
-     * @param \TYPO3\CMS\Core\Resource\File $falFile
-     */
-    public function setFile(\TYPO3\CMS\Core\Resource\File $falFile) {
+    public function setFile(\TYPO3\CMS\Core\Resource\File $falFile): void {
         $this->originalFileIdentifier = (int)$falFile->getUid();
     }
 
diff --git a/Classes/Domain/Model/ImportedEntity.php b/Classes/Domain/Model/ImportedEntity.php
index 2b40582..76c5839 100644
--- a/Classes/Domain/Model/ImportedEntity.php
+++ b/Classes/Domain/Model/ImportedEntity.php
@@ -79,7 +79,7 @@ public function getSourceUniqueIdentifier()
 	/**
 	 * @param string $sourceUniqueIdentifier
 	 */
-	public function setSourceUniqueIdentifier($sourceUniqueIdentifier)
+	public function setSourceUniqueIdentifier($sourceUniqueIdentifier): void
 	{
 		$this->sourceUniqueIdentifier = $sourceUniqueIdentifier;
 	}
@@ -95,7 +95,7 @@ public function getSourceFieldHashes()
 	/**
 	 * @param array $sourceFieldHashes
 	 */
-	public function setSourceFieldHashes($sourceFieldHashes)
+	public function setSourceFieldHashes($sourceFieldHashes): void
 	{
 		$this->sourceFieldHashes = $sourceFieldHashes;
 	}
@@ -111,7 +111,7 @@ public function getInternalUid()
 	/**
 	 * @param int $internalUid
 	 */
-	public function setInternalUid($internalUid)
+	public function setInternalUid($internalUid): void
 	{
 		$this->internalUid = $internalUid;
 	}
@@ -127,7 +127,7 @@ public function getInternalPid()
 	/**
 	 * @param pid $internalPid
 	 */
-	public function setInternalPid($internalPid)
+	public function setInternalPid($internalPid): void
 	{
 		$this->internalPid = $internalPid;
 	}
@@ -143,7 +143,7 @@ public function getInternalEntityClassname()
 	/**
 	 * @param string $internalEntityClassName
 	 */
-	public function setInternalEntityClassName($internalEntityClassname)
+	public function setInternalEntityClassName($internalEntityClassname): void
 	{
 		$this->internalEntityClassname = $internalEntityClassname;
 	}
@@ -159,7 +159,7 @@ public function getInternalLanguage()
 	/**
 	 * @param int $language
 	 */
-	public function setInternalLanguage($internalLanguage)
+	public function setInternalLanguage($internalLanguage): void
 	{
 		$this->internalLanguage = $internalLanguage;
 	}
diff --git a/Classes/Domain/Model/Resource.php b/Classes/Domain/Model/Resource.php
index c3299dd..4331588 100644
--- a/Classes/Domain/Model/Resource.php
+++ b/Classes/Domain/Model/Resource.php
@@ -84,7 +84,7 @@ public function getSource()
 	/**
 	 * @param string $source
 	 */
-	public function setSource($source)
+	public function setSource($source): void
 	{
 		$this->source = $source;
 	}
@@ -100,7 +100,7 @@ public function getSourceData()
 	/**
 	 * @param string $sourceData
 	 */
-	public function setSourceData($sourceData)
+	public function setSourceData($sourceData): void
 	{
 		$this->sourceData = $sourceData;
 	}
@@ -116,7 +116,7 @@ public function getFilename()
 	/**
 	 * @param string $filename
 	 */
-	public function setFilename($filename)
+	public function setFilename($filename): void
 	{
 		$this->filename = $filename;
 	}
@@ -132,7 +132,7 @@ public function getFileObject()
 	/**
 	 * @param \TYPO3\CMS\Core\Resource\File $fileObject
 	 */
-	public function setFileObject($fileObject)
+	public function setFileObject($fileObject): void
 	{
 		$this->fileObject = $fileObject;
 	}
@@ -148,7 +148,7 @@ public function getTitle()
 	/**
 	 * @param string $title
 	 */
-	public function setTitle($title)
+	public function setTitle($title): void
 	{
 		$this->title = $title;
 	}
@@ -164,7 +164,7 @@ public function getDescription()
 	/**
 	 * @param string $description
 	 */
-	public function setDescription($description)
+	public function setDescription($description): void
 	{
 		$this->description = $description;
 	}
diff --git a/Classes/Domain/Repository/ImportedEntityRepository.php b/Classes/Domain/Repository/ImportedEntityRepository.php
index 9b7523f..7f9549b 100644
--- a/Classes/Domain/Repository/ImportedEntityRepository.php
+++ b/Classes/Domain/Repository/ImportedEntityRepository.php
@@ -33,7 +33,7 @@ class ImportedEntityRepository extends \TYPO3\CMS\Extbase\Persistence\Repository
     /**
      *
      */
-    public function initializeObject()
+    public function initializeObject(): void
     {
         $querySettings = $this->createQuery()->getQuerySettings();
         $querySettings->setRespectStoragePage(false);
diff --git a/Classes/Service/AbstractSyncService.php b/Classes/Service/AbstractSyncService.php
index 6cee792..c43eb4a 100644
--- a/Classes/Service/AbstractSyncService.php
+++ b/Classes/Service/AbstractSyncService.php
@@ -30,7 +30,7 @@
 abstract class AbstractSyncService
 {
 
-    public function run() {
+    public function run(): void {
         $this->fetch();
         $this->transform();
         $this->store();
diff --git a/Classes/Service/DomainObjectTranslationService.php b/Classes/Service/DomainObjectTranslationService.php
index e0bbb4a..602597c 100644
--- a/Classes/Service/DomainObjectTranslationService.php
+++ b/Classes/Service/DomainObjectTranslationService.php
@@ -29,11 +29,15 @@
 class DomainObjectTranslationService implements SingletonInterface
 {
     protected \TYPO3\CMS\Extbase\Persistence\Generic\Mapper\DataMapper $dataMapper;
+    public function __construct(\TYPO3\CMS\Extbase\Persistence\Generic\Mapper\DataMapper $dataMapper)
+    {
+        $this->dataMapper = $dataMapper;
+    }
 
     /**
      * Translates a domain object
      */
-    public function translate(DomainObjectInterface $origin, DomainObjectInterface $translation, int $language)
+    public function translate(DomainObjectInterface $origin, DomainObjectInterface $translation, int $language): void
     {
         if (get_class($origin) !== get_class($translation)) {
             throw new \Exception('Origin and translation must be the same type.', 1432499926);
@@ -57,9 +61,4 @@ public function translate(DomainObjectInterface $origin, DomainObjectInterface $
 
         $translation->_setProperty('_languageUid', $language);
     }
-
-    public function injectDataMapper(DataMapper $dataMapper): void
-    {
-        $this->dataMapper = $dataMapper;
-    }
 }
diff --git a/Classes/Service/Extractor/JsonExtractor.php b/Classes/Service/Extractor/JsonExtractor.php
index ce19032..2663db0 100644
--- a/Classes/Service/Extractor/JsonExtractor.php
+++ b/Classes/Service/Extractor/JsonExtractor.php
@@ -31,7 +31,7 @@
 class JsonExtractor extends AbstractExtractor
 {
 
-    protected $content = NULL;
+    protected $content;
 
     protected $source;
 
@@ -46,7 +46,7 @@ public function getContent()
     /**
      * @param mixed $content
      */
-    public function setContent($content)
+    public function setContent($content): void
     {
         $this->content = $content;
     }
@@ -62,18 +62,14 @@ public function getSource()
     /**
      * @param mixed $source
      */
-    public function setSource($source)
+    public function setSource($source): void
     {
         $this->source = $source;
     }
 
     function extract()
     {
-        if (is_null($this->content)) {
-            $rawData = file_get_contents($this->source);
-        } else {
-            $rawData = $this->content;
-        }
+        $rawData = is_null($this->content) ? file_get_contents($this->source) : $this->content;
 
         $jsonData = json_decode($rawData, true);
 
diff --git a/Classes/Service/Extractor/XmlExtractor.php b/Classes/Service/Extractor/XmlExtractor.php
index 9b0d145..afb2bbb 100644
--- a/Classes/Service/Extractor/XmlExtractor.php
+++ b/Classes/Service/Extractor/XmlExtractor.php
@@ -43,7 +43,7 @@ public function getSource()
     /**
      * @param mixed $source
      */
-    public function setSource($source)
+    public function setSource($source): void
     {
         $this->source = $source;
     }
@@ -55,7 +55,7 @@ public function extract()
         $xmlObject = simplexml_load_string($rawData);
 
         if (!is_object($xmlObject)) {
-            throw new \Exception('no xml in response');
+            throw new \Exception('no xml in response', 8369019978);
         }
 
         return $xmlObject;
diff --git a/Classes/Service/Loader/DatahandlerLoader.php b/Classes/Service/Loader/DatahandlerLoader.php
index 31371b8..beef622 100644
--- a/Classes/Service/Loader/DatahandlerLoader.php
+++ b/Classes/Service/Loader/DatahandlerLoader.php
@@ -41,13 +41,9 @@ class DatahandlerLoader extends AbstractLoader
 
     public function load($transformedData)
     {
-
-        foreach ($transformedData as $item) {
-
-        }
     }
 
-    public function process() {
+    public function process(): void {
         /** @var \TYPO3\CMS\Core\DataHandling\DataHandler $dataHandler */
         $dataHandler = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\CMS\Core\DataHandling\DataHandler');
         $dataHandler->start($this->datamap, array());
@@ -55,7 +51,7 @@ public function process() {
 
         if ($dataHandler->errorLog) {
             var_dump($dataHandler->errorLog);
-            throw new \Exception('error while processing datamap');
+            throw new \Exception('error while processing datamap', 4318360878);
         }
 
         unset($dataHandler);
@@ -66,7 +62,7 @@ public function process() {
         $dataHandler->process_cmdmap();
 
         if ($dataHandler->errorLog) {
-            throw new \Exception('error while processing cmdmap');
+            throw new \Exception('error while processing cmdmap', 7879108206);
         }
 
     }
diff --git a/Classes/Service/Loader/SynchronizedLoader.php b/Classes/Service/Loader/SynchronizedLoader.php
index d09ef0f..f7d43b1 100644
--- a/Classes/Service/Loader/SynchronizedLoader.php
+++ b/Classes/Service/Loader/SynchronizedLoader.php
@@ -47,14 +47,12 @@ class SynchronizedLoader extends DatahandlerLoader
 
     public function load($transformedData)
     {
-        foreach ($transformedData as $item) {
-        }
     }
 
     protected function sync(DomainObjectInterface $domainObject, $uniqueIdentifier) {
         $tables = array_keys($this->datamap);
         foreach ($tables as $table) {
-            foreach ($this->datamap[$table] as $id => $fieldArray) {
+            foreach ($this->datamap[$table] as $fieldArray) {
                 if (!is_array($fieldArray)) {
                     continue;
                 }
diff --git a/Classes/Service/ResourceImportService.php b/Classes/Service/ResourceImportService.php
index 14e2a82..9fa1c5e 100644
--- a/Classes/Service/ResourceImportService.php
+++ b/Classes/Service/ResourceImportService.php
@@ -62,10 +62,9 @@ class ResourceImportService
     /**
      * Import a single resource, download the file and store it locally
      *
-     * @param \Sinso\Smartimport\Domain\Model\Resource $resource
      * @throws EmptyContentException
      */
-    public function importResource(\Sinso\Smartimport\Domain\Model\Resource $resource)
+    public function importResource(\Sinso\Smartimport\Domain\Model\Resource $resource): void
     {
         $resourcePathAndFilename = GeneralUtility::getFileAbsFileName($resource->getFilename());
 
@@ -85,7 +84,7 @@ public function importResource(\Sinso\Smartimport\Domain\Model\Resource $resourc
             file_put_contents($resourcePathAndFilename, $resource->getSourceData());
         }
 
-        $fileObject = \TYPO3\CMS\Core\Resource\ResourceFactory::getInstance()->retrieveFileOrFolderObject($resourcePathAndFilename);
+        $fileObject = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Core\Resource\ResourceFactory::class)->retrieveFileOrFolderObject($resourcePathAndFilename);
         $resource->setFileObject($fileObject);
     }
 
@@ -98,11 +97,10 @@ public function importResource(\Sinso\Smartimport\Domain\Model\Resource $resourc
      * TODO: Remove deleted/missing resources from entity
      *
      * @param array<\Sinso\Smartimport\Domain\Model\Resource> $resources
-     * @param \TYPO3\CMS\Extbase\DomainObject\AbstractEntity $entity
      * @param string $tablename
      * @param string $fieldname
      */
-    public function importResourcesToEntity(Array $resources, \TYPO3\CMS\Extbase\DomainObject\AbstractEntity $entity, $tablename, $fieldname) {
+    public function importResourcesToEntity(Array $resources, \TYPO3\CMS\Extbase\DomainObject\AbstractEntity $entity, $tablename, $fieldname): void {
         $datamap = array();
         foreach ($resources as $resource) {
             /** @var \Sinso\Smartimport\Domain\Model\Resource $resource */
@@ -120,7 +118,7 @@ public function importResourcesToEntity(Array $resources, \TYPO3\CMS\Extbase\Dom
             );
         }
 
-        if (!$datamap) {
+        if ($datamap === []) {
             return;
         }
 
@@ -154,7 +152,7 @@ public function isOverwriteExistingFiles()
     /**
      * @param boolean $overwriteExistingFiles
      */
-    public function setOverwriteExistingFiles($overwriteExistingFiles)
+    public function setOverwriteExistingFiles($overwriteExistingFiles): void
     {
         $this->overwriteExistingFiles = $overwriteExistingFiles;
     }
diff --git a/Classes/Service/SimpleSyncService.php b/Classes/Service/SimpleSyncService.php
index 61fe320..70ff185 100644
--- a/Classes/Service/SimpleSyncService.php
+++ b/Classes/Service/SimpleSyncService.php
@@ -30,11 +30,17 @@
 class SimpleSyncService extends AbstractSyncService
 {
 
+    public $defaultLanguage;
+    public $shopItemRepository;
+    public $persistenceManager;
+    public $languages;
+    public $imageFolder;
+    public $resourceImportService;
     protected $model;
 
     protected $tablename;
 
-    public function sync($data) {
+    public function sync($data): void {
         foreach ($itemInAllLanguages as $language => $item) {
             $shopItem = new ShopItem();
             $shopItem->setName($item['name']);
@@ -57,8 +63,10 @@ public function sync($data) {
             }
 
             $resourcesToImport = array();
-
-            if (!is_array($productInformationFromWebScraper) || !is_array($productInformationFromWebScraper['images'])) {
+            if (!is_array($productInformationFromWebScraper)) {
+                continue;
+            }
+            if (!is_array($productInformationFromWebScraper['images'])) {
                 continue;
             }
 
diff --git a/Classes/Service/Transformer/AbstractTransformer.php b/Classes/Service/Transformer/AbstractTransformer.php
index d16e14e..852c926 100644
--- a/Classes/Service/Transformer/AbstractTransformer.php
+++ b/Classes/Service/Transformer/AbstractTransformer.php
@@ -49,7 +49,7 @@ protected function transformFieldValue($field, $value) {
         */
 
         if (!in_array($field, $this->sanitizedFields)) {
-            $value = $this->sanitizeValue($value);
+            return $this->sanitizeValue($value);
         }
 
         return $value;
diff --git a/Configuration/TCA/Overrides/sys_template.php b/Configuration/TCA/Overrides/sys_template.php
new file mode 100644
index 0000000..f5f7a2f
--- /dev/null
+++ b/Configuration/TCA/Overrides/sys_template.php
@@ -0,0 +1,3 @@
+<?php
+
+\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile('smartimport', 'Configuration/TypoScript', 'Swisscom Import Framework');
diff --git a/composer.json b/composer.json
index 9de3cf0..f0ffbc6 100644
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,8 @@
   "type": "typo3-cms-extension",
   "license": "GPL-2.0-or-later",
   "require": {
-    "typo3/cms-core": "^7.4.0 || ^8.7 || ^10.4 || ^11"
+    "php": ">= 8.1 < 8.4",
+    "typo3/cms-core": "^11 || ^12"
   },
   "autoload": {
     "psr-4": {
diff --git a/ext_localconf.php b/ext_localconf.php
deleted file mode 100644
index e61bdb8..0000000
--- a/ext_localconf.php
+++ /dev/null
@@ -1,4 +0,0 @@
-<?php
-if (!defined('TYPO3_MODE')) {
-	die('Access denied.');
-}
diff --git a/ext_tables.php b/ext_tables.php
index 91d21ff..ff0c4c5 100644
--- a/ext_tables.php
+++ b/ext_tables.php
@@ -1,6 +1,4 @@
 <?php
-if (!defined('TYPO3_MODE')) {
+if (!defined('TYPO3')) {
 	die('Access denied.');
 }
-
-\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile('smartimport', 'Configuration/TypoScript', 'Swisscom Import Framework');