how to get foreground notification throughout app flutter code example

Example: flutter local notifications not working for ios foreground

import UIKit
import Flutter
import UserNotifications

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate, UNUserNotificationCenterDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)
    // set the delegate in didFinishLaunchingWithOptions
    UNUserNotificationCenter.current().delegate = self
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
    // This method will be called when app received push notifications in foreground
    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void)
    {
        completionHandler([.alert, .badge, .sound])
    }
}