使用REST API验证电子邮件并注册用户（Dart和Flutter）

Question

我正在尝试使用REST API来注册用户。到目前为止，我无需注册即可注册用户。但是，我需要通过发送确认电子邮件来验证用户的电子邮件，然后在确认后注册用户。我该怎么办？

这是我当前的代码：

class Auth with ChangeNotifier {
  String _token;
  DateTime _expiryDate;
  String _userId;
   Timer _authTimer;

  String get token {
    if (_expiryDate != null &&
        _expiryDate.isAfter(DateTime.now()) &&
        _token != null) {
      return _token;
    }
  }

  bool get isAuth {
    return token != null;
  }

  String get userId{ 
    return _userId; 
  }

  Future<void> _authenticate(
      String email, String password, String urlSegment) async {
    final url =
        '`https://www.googleapis.com/identitytoolkit/v3/relyingparty`/$urlSegment?key={MyAPIKEY}';

    try {
      final response = await http.post(
        url,
        body: json.encode(
          {
            'email': email,
            'password': password,
            'returnSecureToken': true,
          },
        ),
      );
      final responseData = json.decode(response.body);
      if (responseData['error'] != null) {
        throw HttpException(responseData['error']['message']);
      }

      _token = responseData['idToken'];
      _userId = responseData['localId'];
      _expiryDate = DateTime.now()
          .add(Duration(seconds: int.parse(responseData['expiresIn'])));
    
     notifyListeners(); 
    } catch (error) {
      throw error;
    }
  }

  Future<void> signup(String email, String password) async {
    return _authenticate(email, password, 'signupNewUser');
  }
}