How to connect to Localhost? - flutter

Question

I'm here new, I'm learning flutter and I need login with this:
POST http://localhost:3000/api/users/session
But I still can't login :( I'm waiting 5 minutes and still there is a loading screen with no effects.
I have try
So I have have made a this api_service with this tutorial made https://www.youtube.com/watch?v=_Kw4BfNX1-4
here is my api_service.dart
import 'package:http/http.dart' as http;
import 'dart:convert';
import '../model/login_model.dart';
class APIService {
Future<LoginResponseModel>
login(LoginRequestModel requestModel) async {
String url = "http://localhost:3000/api/users/session";
final response = await http.post(url, body: requestModel.toJson());
if (response.statusCode == 200 || response.statusCode == 400) {
return LoginResponseModel.fromJson(
json.decode(response.body),
);
} else {
throw Exception('Failed to load data!');
}
}
}
Here is debug console:
E/flutter (10967): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)]
Unhandled Exception: SocketException: OS Error: Connection refused,
errno = 111, address = localhost, port = 58856 E/flutter (10967):
I'm try with this page:
https://medium.com/#podcoder/connecting-flutter-application-to-localhost-a1022df63130
I change String url = "http://localhost:3000/api/users/session"; to
String url = "http://10.0.2.2:3000/api/users/session";
in my debug console i have completely different messages, but stilll
don't work :(
E/flutter (10967):
[ERROR:flutter/lib/ui/ui_dart_state.cc(186)]
Unhandled Exception: Bad state: Insecure HTTP is not allowed by
platform: http://10.0.2.2:3000/api/users/session
E/flutter (10967): #0 _HttpClient._openUrl
(dart:_http/http_impl.dart:2434:7)
E/flutter (10967): #1 _HttpClient.openUrl
(dart:_http/http_impl.dart:2341:7)
E/flutter (10967): #2 IOClient.send
package:http/src/io_client.dart:31
(...) to #28 and the last ist E/flutter (10967):

Answer 1

Fix for the Error Unhandled Exception: Bad state: Insecure HTTP is not allowed by platform
Flutter terms http as an insecure source Therefore you should either use https or set android:usesCleartextTraffic to true in AndroidManifest
<uses-permission android:name="android.permission.INTERNET" />
<application
android:name="io.flutter.app.FlutterApplication"
android:label="receipt"
android:usesCleartextTraffic="true" // Add this line
android:icon="#mipmap/ic_launcher">