Flutter block push notification permission on iOS at startup

I'm deploying a flutter app and I ve a problem: when run it in iOS device I've a push notification request permission on a startup but I'd like to ask for permission in future screen. In detail I'd like to ask permission to the user in a dedicated page with a button:

Future<NotificationSettings> checkPermissions() async {
    settings = await FirebaseMessaging.instance.requestPermission(
      announcement: true,
      carPlay: true,
      criticalAlert: true,
    );
    return settings;
  }
}

This is my main.dart

import 'dart:async';
import 'package:firebase_core/firebase_core.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';


Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  await Firebase.initializeApp();
  print('------- onBackgroundMessage ----------');
}

// ACTIVATE ANDROID NOTIFICATION IN FOREGROUND
const AndroidNotificationChannel channel = AndroidNotificationChannel(
  'high_importance_channel', // id
  'High Importance Notifications', // title
  'This channel is used for important notifications.', // description
  importance: Importance.high,
);

// ACTIVATE ANDROID NOTIFICATION IN FOREGROUND
final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
    FlutterLocalNotificationsPlugin();

//RemoteMessage globalMessage;

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);

  // ACTIVATE ANDROID NOTIFICATION IN FOREGROUND
  await flutterLocalNotificationsPlugin
      .resolvePlatformSpecificImplementation<
          AndroidFlutterLocalNotificationsPlugin>()
      ?.createNotificationChannel(channel);

  // ACTIVATE IOS NOTIFICATION IN FOREGROUND
  await FirebaseMessaging.instance.setForegroundNotificationPresentationOptions(
    alert: true,
    badge: true,
    sound: true,
  );

  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      routes: {
        '/': (context) => Application(),
        '/pushNotification': (context) => MessageScreen()
      },
    );
  }
}

class Application extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _Application();
}

class _Application extends State<Application> {
  var initializationSettings;
  var initializationSettingsAndroid;
  var initializationSettingsIOS;
  RemoteMessage foregroundMessage;

  @override
  void initState() {
    super.initState();

    print("_Application : inizio initState()");

    initializationSettingsAndroid =
        AndroidInitializationSettings('launch_background');
    initializationSettingsIOS = IOSInitializationSettings(
      requestAlertPermission: true,
      requestBadgePermission: true,
      requestSoundPermission: false,
      onDidReceiveLocalNotification: (id, title, body, payload) async {
        // your call back to the UI
      },
    );
    initializationSettings = InitializationSettings(
        android: initializationSettingsAndroid, iOS: initializationSettingsIOS);

    setOnNotificationClick(onNotificationClick);

    FirebaseMessaging.instance
        .getInitialMessage()
        .then((RemoteMessage message) {
      if (message != null) {
        //Navigator.push(context,
        //new MaterialPageRoute(builder: (context) => new LoginScreen()));
        Navigator.pushNamed(context, '/pushNotification',
            arguments: MessageArguments(message, true));
      }
    });

    FirebaseMessaging.onMessage.listen((RemoteMessage message) {
      RemoteNotification notification = message.notification;
      AndroidNotification android = message.notification?.android;

      foregroundMessage = message;

      print('-------- onMessage ----------');

      //serve per notificare in android quando l'app è in foreground
      if (notification != null && android != null) {
        flutterLocalNotificationsPlugin.show(
            notification.hashCode,
            notification.title,
            notification.body,
            NotificationDetails(
              android: AndroidNotificationDetails(
                channel.id,
                channel.name,
                channel.description,
                // TODO add a proper drawable resource to android, for now using
                //      one that already exists in example app.
                icon: 'launch_background',
              ),
            ),
            payload: message.data.toString());
      }
    });

    FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message) {
      print('---- onMessageOpenedApp ------------------');
      //Navigator.push(context,
      //  new MaterialPageRoute(builder: (context) => new LoginScreen()));
      Navigator.pushNamed(context, '/pushNotification',
          arguments: MessageArguments(message, true));
    });
  }

  setOnNotificationClick(Function onNotificationClick) async {
    await flutterLocalNotificationsPlugin.initialize(initializationSettings,
        onSelectNotification: (String payload) async {
      onNotificationClick(payload);
    });
  }

  onNotificationClick(String payload) {
    print('---- onNotificationClick ------------------');
    print(payload);
    Navigator.pushNamed(context, '/pushNotification',
        arguments: MessageArguments(foregroundMessage, false));
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'XYZ',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      initialRoute: '/',
      onGenerateRoute: RouteGenerator.generateRoute,
    );
  }
}

Do you have any ideas?

thank you