RemovableNotifications_AppDelegate.swift

import UIKit
import UserNotifications

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        application.registerForRemoteNotifications()

        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { (status, error) in
            print(status)
            print(error)
        }

        return true
    }

    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        let hexString = deviceToken.map { String(format: "%02hhx", $0) }.joined()
        print(hexString)
    }

    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
        guard let idToDelete = userInfo["del-id"] as? String else {
            completionHandler(.noData)
            return
        }

        UNUserNotificationCenter.current().removeDeliveredNotifications(withIdentifiers: [idToDelete])
        completionHandler(.noData)
    }
}