We would like to have a Firebase Google and Anonymous Sign-In option for the user on a blank Ionic 4 project. If the sign-in happens with Google the user should also be asked to allow Gmail access. This Gmail access should still be possible after closing and opening the app. (So I think you would have to take care of the access_token refreshing, if I'm not wrong.) We do NOT need any pretty UI. You just have to provide some random UI, so the functionality can be test. We just need the code to see how to do it and then we would implement it in our existing app.