getAuthToken method
The current token, or null when signed out.
Throws when a token cannot currently be obtained — see rule 2 above.
Implementation
@override
Future<String?> getAuthToken({bool forceRefresh = false}) async {
final error = tokenError;
if (error != null) throw error;
if (_identity == null) return null;
return 'token-${_identity!.id}-$_rotation';
}