This project was bootstrapped with Create Contentful App.
This app is a proof of concept app. Code quality is low, shortcuts included.
The sidebar app can be added to any content type. It will allow the user to select the text field (ideally slug field) from which the Tiny URL should be created.
In addition, the app has a configuration page to add the base URL for the website, and the Tiny URL API key.
Install the app and add the Tiny URL API key and the base URL (your full URL) to the configuration page during the installation process. Head over to the content types that should use the sidebar app and add the widget to it.
This app is using Forma 36 – Contentful's design system, and Contentful Field Editors – Contentful's field editor React components to ensure the app continues the look and feel of Contentful, and reuses as much functionality as possible without reinventing the wheel.

