How to use routes in MaterialApp widget

 First, use it in your MaterialApp Widget like this,

class MyApp extends StatelessWidget {

  const MyApp({super.key});

  // This widget is the root of your application.

  @override

  Widget build(BuildContext context) {

    return MaterialApp(

      home: LoginScreen(),

      routes: {

        '/log': (context) => const LoginScreen(),

        '/reg': (context) => const SignupScreen(),

      },

    );

  }

}

Then, You can use it, like this

onTap: (() {

                              Navigator.pushNamed(context, '/reg');

                            }