ios notification not working on background, foreground

I want to use notification when app pause mode(foreground) and app kill (background),

Only notification working on when the app opens (app running). I used this on Flutter project.

enable Background Mode(Background fetch, Remote notifications) and push notification

Code Block 
@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
		override func application(
				_ application: UIApplication,
				didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
		) -> Bool {
			 
				Messaging.messaging().delegate = self
			 
				
				if #available(iOS 10.0, *) {
						UNUserNotificationCenter.current().delegate = self
						
						let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
						UNUserNotificationCenter.current().requestAuthorization(
								options: authOptions,
								completionHandler: {granted, error in print("Permission granted: \(granted)") })
				}else{
						let settings: UIUserNotificationSettings =
								UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
						application.registerUserNotificationSettings(settings)
				}
				GeneratedPluginRegistrant.register(with: self)
				application.registerForRemoteNotifications()
				return super.application(application, didFinishLaunchingWithOptions: launchOptions)
		}
		
		func connectToFcm() {
				Messaging.messaging().shouldEstablishDirectChannel = true
		}
		
		override func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
		 
				createNotifications(userInfo: userInfo)
		}
		
		override func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any],
															fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
		 
				let state : UIApplicationState = application.applicationState
				if (state == .inactive || state == .background) {
					
						createNotifications(userInfo: userInfo)
				} else {
					
						createNotifications(userInfo: userInfo)
				}
				completionHandler(UIBackgroundFetchResult.newData)
		}
		
		override func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
			//
		}
		
		override func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
		 
				connectToFcm()
		}
		
		@available(iOS 10.0, *)
		override func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
			
				completionHandler([.alert, .badge, .sound])
		}
		
				override func applicationDidBecomeActive(_ application: UIApplication) {
						 UIApplication.shared.applicationIconBadgeNumber = 0
					 
						 connectToFcm()
				 }
		
		override func application(_ application: UIApplication, performFetchWithCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
				
			
				completionHandler(.newData)
				
		}
		
		func messaging(_ messaging: Messaging, didRefreshRegistrationToken fcmToken: String) {
				
				//				 if let token = InstanceID.instanceID().token() {
				//						 AppDelegate.DEVICE_ID = token
				//						 print("*******")
				//						 print("Token Instance: \(token)")
				//						 print("*******")
				//				 }
			 
				connectToFcm()
		}
		
		//		override func applicationDidEnterBackground(_ application: UIApplication) {
		//				Messaging.messaging().shouldEstablishDirectChannel = false
		//				print("Disconnect FCM")
		//		}
		
		func createNotifications(userInfo: [AnyHashable: Any]) {
				if #available(iOS 10.0, *) {
				 
						let notificationContent = UNMutableNotificationContent()
						notificationContent.title = userInfo["title"] as! String
						notificationContent.body = userInfo["body"] as! String
						notificationContent.sound = UNNotificationSound.default()
						notificationContent.badge = NSNumber(integerLiteral: UIApplication.shared.applicationIconBadgeNumber + 1)
						notificationContent.threadIdentifier = userInfo["groupKey"] as! String
						if #available(iOS 12.0, *) {
								notificationContent.summaryArgument = userInfo["groupKey"] as! String
						} else {
								// Fallback on earlier versions
						}
						let request = UNNotificationRequest(identifier: UUID.init().uuidString, content: notificationContent, trigger: nil)
						let center = UNUserNotificationCenter.current()
						center.add(request) { (error: Error?) in
								if let theError = error {
										print("error \(theError)")
								}
						}
				}
		}
}
extension AppDelegate : MessagingDelegate{
		func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String) {
		 
				let dataDict:[String: String] = ["token": fcmToken]
				NotificationCenter.default.post(name: Notification.Name("FCMToken"), object: nil, userInfo: dataDict)
		}
 
}

payload looks like this

Code Block 
const payload = {
	"data": {
			title: title,
			body: contentMessage,
			groupKey : groupKey
	},

token: pushToken,

Code Block 
}