How to add swipe back gesture

extension UINavigationController: UIGestureRecognizerDelegate {
  override open func viewDidLoad() {
    super.viewDidLoad()
    interactivePopGestureRecognizer?.delegate = self
  }

  public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
    return viewControllers.count > 1
  }
}