feat: add refreshAccessToken() API

README.md

@@ -218,6 +218,17 @@ getUserInfo(accessToken).then((resp) => {
 });
 ```
 
+#### Refresh access token
+
+You could use a refresh token, to get a new token from the oauth server when token expired.
+
+```typescript
+sdk.refreshAccessToken(refreshToken).then((resp) => {
+    const token = resp.access_token;
+    // Do stuff with new access token
+});
+```
+
 #### A note on Storage
 By default, this package will use sessionStorage to persist the pkce_state. On (mostly) mobile devices there's a higher chance users are returning in a different browser tab. E.g. they kick off in a WebView & get redirected to a new tab. The sessionStorage will be empty there.
 

src/sdk.ts

@@ -352,6 +352,10 @@ class Sdk {
             throw new Error(error.message);
         }
     }
+
+    public refreshAccessToken(refreshToken: string): Promise<ITokenResponse> {
+        return this.pkce.refreshAccessToken(refreshToken);
+    }
 }
 
 export default Sdk;