react native ios willPresentNotification function doesn't handle push notification in the foreground

I want to handle react native FCM with react native firebase messaging .For IOS i added required code to my AppDelegate.mI added willPresentNotification function to handle push when app is in foreground :

//Called when a notification is delivered to a foreground app.-(void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler{  completionHandler(UNAuthorizationOptionSound | UNAuthorizationOptionAlert | UNAuthorizationOptionBadge);}

Currently i'm not receiving push in the foreground and i want to handle this natively.Any suggestion please ?