HandshakeException：客户端中的握手错误（操作系统错误：CERTIFICATE_VERIFY_FAILED：ok（handshake.cc:354））

Question

登录Flutter应用程序时出现以下错误。

HandshakeException：客户端中的握手错误（操作系统错误： CERTIFICATE_VERIFY_FAILED：好的（handshake.cc:354））

该如何删除该错误？

String token;

class LoginService {
  final String _url =
      "....";
  http.Client _client;

  LoginService() {
    _client = IOClient();
  }

  LoginService.customClient(this._client);

  Future<LoginResponse> login(String username, String password) async {
    final response = await _client.post(
      _url + "/login",
      headers: {'Content-Type': 'application/json'},
      body:
          '{"username": "$username","password": "$password","uuid": "$_uuid"}',
    );

    if (response.statusCode == 200 || response.statusCode == 201) {
      Map<String, dynamic> responseJson = json.decode(response.body);
      token = LoginResponse.fromJson(responseJson).getToken;
      return LoginResponse.fromJson(responseJson);
    } else {
      throw Exception("Error logging in");
    }
  }
}