Registration
in AppDelegate
import UserNotifications
in didFinishLaunchingWithOptions method,
UNUserNotificationCenter.current().requestAuthorization(options: [.alert,.sound,.badge]) { (granted, error) in
// Here you can check Request is Granted or not.
}
Create and Schedule notification.
    let content = UNMutableNotificationContent()
    content.title = "10 Second Notification Demo"
    content.subtitle = "From Wolverine"
    content.body = "Notification after 10 seconds - Your pizza is Ready!!"
    content.categoryIdentifier = "myNotificationCategory"
    let trigger = UNTimeIntervalNotificationTrigger(
        timeInterval: 10.0,
        repeats: false)
    
    let request = UNNotificationRequest(
        identifier: "10.second.message",
        content: content,
        trigger: trigger
    )
    UNUserNotificationCenter.current().add(request, withCompletionHandler: nil)
Where ever this part of code is triggered, If you have allowed Notification Permission, you will receive an notification.
To test it properly, Make sure your application in Background mode.
 
                