Notification4.swift

//Here you decide whether to silently handle the notification or still alert the user.
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void)
{
    //Write you app specific code here
    completionHandler([.alert, .sound]) //execute the provided completion handler block with the delivery option (if any) that you want the system to use. If you do not specify any options, the system silences the notification.
}