[Firebase Authentication] Github custom domain OAuth not working on Android

[khang-nd]

I managed to set up a custom domain (https://auth.xxx.com/__/auth/handler) for Firebase Authentication in my project, and it works fine on web since I modified the authDomain in the firebase config.

However, on Android, it appears the default domain (https://xxx.firebaseapp.com__/auth/handler) is still invoked initially and only after the authentication process, it redirects to the custom domain, which then effectively causes an issue that the auth token does not persist on the custom domain and the Firebase cannot login the users. And as the Android version of Firebase Auth relies on a google-services.json, which doesn't expose the authDomain field to be configured, so I'm totally blocked.

Does anyone have the same problem? Did you manage to resolve this issue? Thank you for reading.

[robingenz]

This does not seem to be supported by Firebase at the moment, see firebase/firebase-android-sdk#4805 (comment).