ошибка при реализации запроса на регистрацию пользователя

Привет я реализую регистрациюпользователя и столкнулся с ошибкой которую не могу решить код файла :`

import 'dart:js_interop';

import 'package:bloc/bloc.dart';
import 'package:equatable/equatable.dart';
import 'package:dio/dio.dart';
import 'package:auto_route/auto_route.dart';
import 'package:restapi_client/restapi_client.dart';

part 'signup_event.dart';
part 'signup_state.dart';

class SignupBloc extends Bloc<SignupEvent, SignupState> {
  final RestApiClient restApiClient;
  final StackRouter router;

  SignupBloc({
    required this.restApiClient,
    required this.router,
  }) : super(const SignupState()) {
    on<SignupEvent>(_onEvent);
  }

  Future<void> _onEvent(SignupEvent event, Emitter<SignupState> emit) async {
    if (event is SignupChangeFirstName) {
      emit(state.copyWith(firstName: event.firstName));
    } else if (event is SignupChangeLastName) {
      emit(state.copyWith(lastName: event.lastName));
    } else if (event is SignupChangeEmail) {
      emit(state.copyWith(email: event.email));
    } else if (event is SignupChangePassword) {
      emit(state.copyWith(password: event.password));
    } else if (event is SignupTry) {
      await _attemptSignUp(emit);
    }
  }

  Future<void> _attemptSignUp(Emitter<SignupState> emit) async {
    emit(state.copyWith(loading: true));

    try {
      final RegisterResponse response = await restApiClient.userApi.register(
        email: state.email,
        password: state.password,
        firstName: state.firstName,
        lastName: state.lastName,
        // Добавьте другие необходимые поля
      );

      if (response.token.isNotEmpty) {
        restApiClient.onAuthTokenChanged(response.token, response.user);
        await router.replace(MeetPeopleMapRoute());
      } else {
        emit(state.copyWith(loading: false, errorMessage: "Ошибка регистрации"));
      }
    } 
    catch (e) {
      emit(state.copyWith(loading: false, errorMessage: "Произошла неизвестная ошибка: $e"));
    }
  }

 
}

// Маршрут MeetPeopleMapRoute, как определено в AppRouter class MeetPeopleMapRoute extends PageRouteInfo { MeetPeopleMapRoute() : super(name, args: '/map');

static const String name = 'MeetPeopleMapRoute'; }

[![вот фото ошибок ][1]][1]

    Future<User> register(
    String firstName,
    String lastName,
    String email,
    String password,
  ) async {
    try {
      final resp = await dio.post<Map<String, dynamic>>(
        '/user/register',
        data: RegisterRequest(
          firstName,
          lastName,
          email,
          password,
        ).toJson(),
      );
      final result = RegisterResponse.fromJson(resp.data!);
      tokenHandler.onAuthTokenChanged(result.token, result.user);
      return result.user;
    } catch (error, stackTrace) {
      throwApiError(error, stackTrace);
    }
  }