Home>
I want to return by swiping back the PageViewController whose TransitonStyle in the hierarchy of UINavigationController is scroll

PageViewController in the hierarchy of UINavigationController can be swiped back when TransitionStyle is pageCurl, but if TransitionStyle is set to scroll, swipeback does not react and View moves.
I want to be able to swipe this back even when Transiton Style is scroll

Applicable source code
class TestPageViewController: UIViewController {
    private var controllers: [UIViewController] = []
    private var pageViewController: UIPageViewController!
    override func viewDidLoad() {
        super.viewDidLoad()
        let colors: [UIColor] = [.red, .orange]
        controllers = colors.map (color in
            let vc = UIViewController()
            vc.view.backgroundColor = color
            return vc
        }
        self.pageViewController = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
        self.pageViewController.setViewControllers([self.controllers[0]], direction: .forward, animated: true, completion: nil)
        self.pageViewController.dataSource = self
        self.pageViewController.delegate = self
        self.addChild(self.pageViewController)
        self.view.addSubview(self.pageViewController.view!)
    }

}
extension TestPageViewController: UIPageViewControllerDataSource {
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) ->UIViewController? {
        if let index = controllers.firstIndex(of: viewController),
            index >0 {
            return controllers[index-1]
        } else {
            return nil
        }
    }
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) ->UIViewController? {
        if let index = controllers.firstIndex(of: viewController),
            index<controllers.count-1 {
            return controllers[index+1]
        } else {
            return nil
        }
    }
    func presentationCount(for pageViewController: UIPageViewController) ->Int {
        return controllers.count
    }
}
extension TestPageViewController: UIPageViewControllerDelegate {
}
Addition Transition from this ViewController to the above PageViewController
class FirstViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }
    @IBAction func tap(_ sender: Any) {
        let testVC = TestPageViewController.instantiate()
        navigationController?.pushViewController(testVC, animated: true)
    }
}