AndroidのViewPagerのように横スライドで画面を切り替えたい

Question

参考サイトをみて実装しようと下記の様にコードを書いてみたのですが全く表示されずに困っています。

サイトではPageContentViewControllerを使っているところを個々にViewControllerを用意して埋め込もうとしています。
それ以外はサイトの通りにやっているつもりなのですが、ViewControllerが表示された時PageViewContorollerが表示されませんし、もちろんスライドしても切り替わることもないです。

どこをどの様に修正すれば良いでしょうか？
よろしくお願いします。

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // コンテナに追加
        let pageVC = PageViewController(transitionStyle: .scroll,
                                        navigationOrientation: .horizontal,
                                        options: nil)
        let pageViewHeight: CGFloat = 100
        pageVC.view.frame = CGRect(x: 0, y: view.bounds.size.height - pageViewHeight, width: view.bounds.size.width, height: pageViewHeight)
        
        addChildViewController(pageVC)
        view.addSubview(pageVC.view)
        pageVC.didMove(toParentViewController: self)
        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}
コード

import UIKit

class PageViewController: UIPageViewController,UIPageViewControllerDataSource,UIPageViewControllerDelegate{
    
    var contentVCs = [UIViewController]()
    var currentIndex: Int = 0
    
    override func viewDidLoad() {
        super.viewDidLoad()
        dataSource = self
        delegate = self
        let contentVC = ViewController1()
        let contentVC2 = ViewController2()
        contentVCs.append(contentVC)
        contentVCs.append(contentVC2)
        setViewControllers([contentVCs[0]], direction: .forward, animated: true, completion: nil)
    

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        guard let index = contentVCs.index(of: viewController), index != NSNotFound else { return nil }
        if index > 0 {
            return contentVCs[index - 1]
        } else {
            return contentVCs.last
        }
    }
    
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        guard let index = contentVCs.index(of: viewController), index != NSNotFound else { return nil }
        if index < contentVCs.count - 1 {
            return contentVCs[index + 1]
        } else {
            return contentVCs.first
        }

    }
    
    func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
        return contentVCs.count
    }
    
    func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
        return currentIndex
    }

    func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
        guard finished else { return }
        guard let contentVC = pageViewController.viewControllers?.first else { return }
        guard let index = contentVCs.index(of: contentVC), index != NSNotFound else { return }
        
        currentIndex = index
    }

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}
コード