For this demo, we need the client ID. For the demo the browser will play server and client part of the external app at the same time. You'll find the server code in externalAppServerCode.js and the browser/client code in externalAppBrowserCode.js

Client ID:

Client Secret:

Step 1

redirect to openexperience.de (with state variable), login (if not already happened), approve (if necessary), redirect back here with the code and state

Step 2

send code to server. The server will request the refresh token