flutter-examples/navigation_drawer/lib/main.dart

import 'package:flutter/material.dart';
import 'package:navigation_drawer/example.dart';
import 'package:navigation_drawer/screens/account.dart';
import 'package:navigation_drawer/screens/settings.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: const Example(), // route for home is '/' implicitly
      routes: <String, WidgetBuilder>{
        // define the routes
        SettingsScreen.routeName: (BuildContext context) => SettingsScreen(),
        AccountScreen.routeName: (BuildContext context) => AccountScreen(),
      },
    );
  }
}