How to simplify UIApplication life cycle observation in iOS

final class LifecyclerHandler {
    private var observer: AnyObject!
    var action: (() -> Void)?
    private let debouncer = Debouncer(delay: 1.0)

    func setup() {
        observer = NotificationCenter.default.addObserver(
            forName: UIApplication.didBecomeActiveNotification,
            object: nil,
            queue: .main,
            using: { [weak self] _ in
                self?.debouncer.run {
                    self?.action?()
                }
        })
    }
}

private let lifecycleHandler = LifecyclerHandler()

override func viewDidLoad() {
    super.viewDidLoad()

  
    lifecycleHandler.action = {
        Deps.userHandler.refreshToken()
    }

    lifecycleHandler.setup()
}