Apple Login with Flutter and Firebase is not saving the private relay emails

Question

We are allowing login via Apple in our Flutter/Firebase app.

Following these instructions we have enabled apple as a sign in provider:

The sign in via apple all works fine,
However we are not getting the private relay email saved in the Authentication in Firebase,
instead it is coming through as null:

What do we need so that the private relay email comes through via an Apple sign up?

Answer 1

The email is found in the additionalUserInfo when signing in. I haven't found a way yet to let firebase set the email and I the only way I found, was to set it manually like this:

final userCredential = await auth.signInWithProvider(
          AppleAuthProvider().addScope('email'),
        );
final email = userCredential.additionalUserInfo?.profile?['email'] as String;
userCredential.user?.verifyBeforeUpdateEmail(email);

This of course implies that a verification email with link is sent, on which the user has to click.