code:

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        let center = UNUserNotificationCenter.current()
        // Request permission to display a badge.
        center.requestAuthorization(options: [.badge]) { (granted, error) in
            DispatchQueue.main.async {
                application.applicationIconBadgeNumber = Int.max
            }
        }
        return true
    }