UIApplication.shared.setMinimumBackgroundFetchInterval(30)

func application(_ application: UIApplication, performFetchWithCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {

    debugPrint("New notification fired from AppDelegate...!!")

    let notif = UNMutableNotificationContent()
    notif.title = "New notification from App delegate"
    notif.subtitle = "Cool App!"
    notif.body = "I liked it!"

    UNUserNotificationCenter.current().requestAuthorization(options: [.sound, .badge, .alert], completionHandler: { (isGranted, error) in

        DispatchQueue.main.async {
            let notifTrigger = UNTimeIntervalNotificationTrigger(timeInterval: 0.1, repeats: false)
            let request = UNNotificationRequest(identifier: "myNotification", content:  notif, trigger: notifTrigger)

            UNUserNotificationCenter.current().add(request) { (error) in
                if error != nil{
                    print(error!)
                } else {
                    // do something
                }
            }
        }
    })

}