Amplify plugin was not added (Flutter)

import 'package:amplify_analytics_pinpoint/amplify_analytics_pinpoint.dart';
import 'amplifyconfiguration.dart';
import 'package:amplify_auth_cognito/amplify_auth_cognito.dart';
import 'package:amplify_flutter/amplify.dart';
import 'package:amplify_core/amplify_core.dart';
import 'package:flutter/material.dart';
import 'package:sing_in_test/login_page.dart';


void main() {
  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  bool _amplifyConfigured = false;
  late  AmplifyAuthCognito auth;
  late AmplifyAnalyticsPinpoint analyticsPinpoint;
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _configureAmplify();
  }
  void  _configureAmplify() async {
    if(!mounted) return;
    auth = AmplifyAuthCognito();
    analyticsPinpoint = AmplifyAnalyticsPinpoint();
    await Amplify.addPlugin(auth);
    await Amplify.addPlugin(analyticsPinpoint);
    try {
      await Amplify.configure(amplifyconfig);

    } on AmplifyAlreadyConfiguredException{
      print('Alredy configured');
    }


    try {
      setState(() {
        _amplifyConfigured = true;
      });
    } catch (e) {
      print(e);
    }
  }
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: Text('AWS'),
          centerTitle: true,
        ),
        body: _amplifyConfigured ? LoginPage():Text('Loading'),
      ),

    );
  }
}