I use this code the create a custom tabBar:

class TabBarViewController: UITabBarController {

    let tabBarView = UIView()
    let blurView = UIVisualEffectView(effect: UIBlurEffect(style: .systemChromeMaterialLight))
    
    override func viewDidLoad() {
        super.viewDidLoad()
        generateTabBar()
        setupTabBarAppearance()
    }
    
    func generateTabBar() {
        viewControllers = [
            generateVC(controller: UINavigationController(rootViewController: TableViewController()),
                       title: TableViewController().title!,
                       image: TableViewController().image),
            generateVC(controller: UINavigationController(rootViewController: FavoritesController()),
                       title: FavoritesController().title!,
                       image: FavoritesController().image),
            generateVC(controller: UINavigationController(rootViewController: SearchViewController()),
                       title: SearchViewController().title!,
                       image: SearchViewController().image)]
    }
    
    func generateVC(controller: UIViewController, title: String, image: UIImage?) -> UIViewController {
        controller.tabBarItem.title = title
        controller.tabBarItem.image = image
        return controller
    }
    
    private func setupTabBarAppearance(){
        
        tabBar.backgroundImage = UIImage()
        tabBar.backgroundColor = .clear
        tabBar.shadowImage = UIImage()
        tabBar.itemWidth = (tabBar.bounds.width - 10) / 5
        tabBar.itemPositioning = .centered
        tabBar.tintColor = .green
        tabBar.unselectedItemTintColor = .red

        view.addSubview(tabBarView)
        
        tabBarView.backgroundColor = .clear
        tabBarView.translatesAutoresizingMaskIntoConstraints = false
        
        let scenes = UIApplication.shared.connectedScenes
        let windowScene = scenes.first as? UIWindowScene
        let window = windowScene?.windows.first
        
        tabBarView.frame = CGRect(x: 32, y: window!.frame.size.height - tabBar.frame.size.height - SafeArea().bottom() - 5, width: tabBar.frame.size.width - 64, height: tabBar.frame.size.height + 10)
        
        tabBarView.layer.cornerRadius = (tabBar.frame.size.height+5)/2
        
        view.bringSubviewToFront(tabBar)
        
        blurView.translatesAutoresizingMaskIntoConstraints = false
        blurView.clipsToBounds = true
        
        blurView.frame = CGRect(x: 0, y:0, width: tabBarView.frame.size.width, height: tabBarView.frame.size.height)
        
        blurView.layer.cornerRadius = (tabBar.frame.size.height+5)/2
        tabBarView.addSubview(blurView)
        
        blurView.layer.cornerRadius = (tabBar.frame.size.height+5)/2.25
        
        tabBarView.bringSubviewToFront(blurView)
        
    }
}

And I want to hide my tabBar when I scrolling the view. I use this code to do it:

func changeTabBar(hidden:Bool, animated: Bool){
    guard let tabBar = self.tabBarController?.tabBar else { return }
    let offset = (hidden ? UIScreen.main.bounds.size.height : UIScreen.main.bounds.size.height - (tabBar.frame.size.height))
    if offset == tabBar.frame.origin.y {return}
    let duration:TimeInterval = (animated ? 0.5 : 0.0)
    UIView.animate(withDuration: duration, animations: { tabBar.frame.origin.y = offset }, completion:nil)
}

func scrollViewDidScroll(_ scrollView: UIScrollView) {
    if scrollView.panGestureRecognizer.translation(in: scrollView).y < 0{
        changeTabBar(hidden: true, animated: true)
    } else {
        changeTabBar(hidden: false, animated: true)
    }
}

But in this case only the tab bar items are hidden and my tabBarView and blurView are not hidden.