Node.js注册API在Thunder Client正常，集成Flutter后失效求助

我用Node.js开发了注册API，在Thunder Client中测试运行正常，但集成到Flutter项目后无法正常工作。此前使用类似的API和Flutter代码均无问题，但本次点击注册按钮时出现错误。

错误截图 #

Node.js API代码截图 #

Flutter API集成代码截图 #

Flutter注册页面完整代码 #

import 'package:flutter/material.dart';
import 'package:order_eats/APIS/user_api.dart';
import 'package:order_eats/screens/auth_screens/login.dart';
import 'package:order_eats/screens/auth_screens/widgets/custom_button.dart';
import 'package:order_eats/screens/auth_screens/widgets/custom_field.dart';

class SignUp extends StatefulWidget {
  const SignUp({super.key});

  static const routeName = '/signup';

  @override
  State<SignUp> createState() => _SignUpState();
}

class _SignUpState extends State<SignUp> {
  final TextEditingController emailController = TextEditingController();
  final TextEditingController passwordController = TextEditingController();
  final TextEditingController nameController = TextEditingController();
  final formKey = GlobalKey<FormState>();

  void userSignup() {
    UserApis().userSignUP(context, emailController.text,
        passwordController.text, nameController.text);
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Padding(
            padding: const EdgeInsets.all(10),
            child: Form(
              key: formKey,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Container(
                    margin: const EdgeInsets.symmetric(horizontal: 20),
                    child: const Text(
                      'Order Eats',
                      style: TextStyle(
                          fontSize: 25,
                          fontWeight: FontWeight.w900,
                          color: Color.fromRGBO(255, 97, 164, 1)),
                    ),
                  ),
                  const SizedBox(
                    height: 20,
                  ),
                  const Text(
                    'Lets get started',
                    style: TextStyle(
                        fontSize: 20,
                        color: Colors.black,
                        fontWeight: FontWeight.bold),
                  ),
                  const SizedBox(
                    height: 20,
                  ),
                  CustomField(name: 'Name', controller: nameController),
                  const SizedBox(
                    height: 20,
                  ),
                  CustomField(
                    name: 'Email',
                    controller: emailController,
                  ),
                  const SizedBox(
                    height: 20,
                  ),
                  CustomField(name: 'Password', controller: passwordController),
                  const SizedBox(
                    height: 20,
                  ),
                  CustomButton(
                      ontap: () {
                        if (formKey.currentState!.validate()) {
                          userSignup();
                        }
                      },
                      text: 'Sign Up'),
                  const SizedBox(
                    height: 20,
                  ),
                ],
              ),
            ),
          ),
          Row(
            children: [
              const Text(
                'Already have an account? ',
                style: TextStyle(
                  color: Colors.black,
                ),
              ),
              GestureDetector(
                onTap: () =>
                    Navigator.of(context).pushNamed(LoginScreen.routeName),
                child: const Text(
                  'Login',
                  style: TextStyle(
                      color: Color.fromRGBO(255, 97, 164, 1),
                      fontWeight: FontWeight.bold),
                ),
              )
            ],
          )
        ],
      ),
    );
  }
}

内容的提问来源于stack exchange，提问作者Umair