Add Firebase Authentication To Your App Tutorial

Add Firebase Authentication to your App in 7minutes

        FirebaseUser user = mAuth.getInstance().getCurrentUser();
If (user!= null){
String email = user.getEmail();
String Uid = user.getUid();
}

        if(user !=null){
        
          mAuth.signOut
}

Source: https://medium.com/@kenny_io/add-firebase-authentication-to-your-app-in-7minutes-c13df58994bd