debugShowCheckedModeBanner Not remove debugShowCheckedModeBanner:false – Flutter

I’m trying to remove the debug banner from my application and I added debugShowCheckedModeBanner: false in my main.dart and every activity but still showing the debug banner.

Main.dart

import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:intrackapp/login/splash_screen.dart';
import 'package:khalti_flutter/khalti_flutter.dart';
import 'login/firebase_options.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );

  runApp( MyApp());
}

class MyApp extends StatelessWidget {
  final usernameController = TextEditingController();
  final passwordController = TextEditingController();
  MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
    @override
    Widget build(BuildContext context) {
     return KhaltiScope(
       publicKey: "test_public_key_6ddec90a98d44awe4d84e2c58fc172490a",
       builder: (context, navKey) {
         return MaterialApp(
          // debugShowCheckedModeBanner: false,
           navigatorKey: navKey,
           localizationsDelegates: const[KhaltiLocalizations.delegate],
           theme: ThemeData(
             primaryColor: Colors.grey, // Set default color to blue
           ),

               debugShowCheckedModeBanner: false,
               home: SplashScreen(),
         );
       }
     );
  }
}

The major issue is debugShowCheckedModeBanner: false is not removing the debug banner because the debug banner shows on every page. How to remove the debug banner?