Sample main.dart for navigating with GlobalObjectKey

main.dart

import 'package:flutter/material.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: SizedBox(
            width: 300,
            height: 300,
            child: Navigator(
              key: const GlobalObjectKey<NavigatorState>('navigator'),
              onGenerateRoute: (settings) => MaterialPageRoute(
                builder: (_) => const FirstPage(),
              ),
            ),
          ),
        ),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: () {
        const key = GlobalObjectKey<NavigatorState>('navigator');
        key.currentState?.push(
          MaterialPageRoute(builder: (_) => const NextPage()),
        );
      },
      child: const ColoredBox(
        color: Colors.blue,
        child: Center(child: Text('First')),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: () {
        const key = GlobalObjectKey<NavigatorState>('navigator');
        key.currentState?.pop();
      },
      child: const ColoredBox(
        color: Colors.green,
        child: Center(child: Text('Next')),
      ),
    );
  }
}