Flutter Nav Drawer Not Working

import 'package:flutter/material.dart';

import 'package:routemaster/routemaster.dart';


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

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      routerDelegate: RoutemasterDelegate(routesBuilder: (context) => routes),
      routeInformationParser: const RoutemasterParser(),
    );
  }
}


final routes = RouteMap(
  routes: {
    '/':(route) => const MaterialPage(
      key: ValueKey('first'),
      child: firstPage,
    ),
    '/second':(route) => const MaterialPage(
      key: ValueKey('second'),
      child: secondPage,
    ),
  },
);


const firstPage = AppPage(
  title: Text('First'),
  body: Text('First'),
  color: Colors.purple
);


const secondPage = AppPage(
  title: Text('Second'),
  body: Text('Second'),
  color: Colors.green
);


class AppPage extends StatelessWidget {
  final Text title;
  final Text body;
  final Color color;

  const AppPage({
    super.key,
    required this.title,
    required this.body,
    required this.color
  });

  @override
  Widget build (BuildContext context) {
    return Scaffold(
      drawer: Drawer(
        child: ListView(
          children: [
            ListTile(
              title: const Text('First'),
              onTap: () => Routemaster.of(context).push('/'),
            ),
            ListTile(
              title: const Text('Second'),
              onTap: () => Routemaster.of(context).push('/second'),
            ),
          ],
        ),
      ),
      appBar: AppBar(
        title: title,
      ),
      body: Container(
        decoration: BoxDecoration(color: color),
        child: Center(child: body),
      ),
    );
  }
}