I'm using Sign in with Apple in the app together with Firebase Auth. It works as expected.
I'm also developing an App Clip. It works the same as in the parent app, but I want to migrate credentials when the user migrates to the parent app. That's all good but in order to sign in user to Auth, it requires token in order to create an OAuthProvider.credential.
The documentation says that we should store credential userId to the shared user defaults. But I don't want to store the credential in here.
There is also an article to implement cross-app authentication using shared keychain, which unfortunately is not available for App Clips.
Does anyone have a clue how to migrate Sign in with Apple credentials from App Clip to the parent app using Firebase Auth?