```dart
Future<void> verifyAttributeUpdate() async {
  try {
    await Amplify.Auth.confirmUserAttribute(
      userAttributeKey: CognitoUserAttributeKey.email,
      confirmationCode: '390739',
    );
    print('Attribute verified');
  } on AmplifyException catch (e) {
    print(e.message);
  }
}
```