Add Close button to a popover that presents full screen modal in horizontal compact

ViewController.swift

import UIKit

class ViewController: UIViewController, UIPopoverPresentationControllerDelegate {

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        super.prepare(for: segue, sender: sender)
        segue.destination.popoverPresentationController?.delegate = self
    }
    
    // MARK: - UIPopoverPresentationControllerDelegate
    
    func presentationController(_ controller: UIPresentationController,
                                viewControllerForAdaptivePresentationStyle style: UIModalPresentationStyle) -> UIViewController? {

        if let navController = controller.presentedViewController as? UINavigationController {
            navController.children.first?.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Close", style: .plain, target: self, action: #selector(didTapClose(_:)))
        }
        
        return controller.presentedViewController
    }
    
    func presentationController(_ presentationController: UIPresentationController,
                                willPresentWithAdaptiveStyle style: UIModalPresentationStyle,
                                transitionCoordinator: UIViewControllerTransitionCoordinator?) {
    
        if let navController = presentationController.presentedViewController as? UINavigationController, style == .none {
            navController.children.first?.navigationItem.rightBarButtonItem = nil
        }
    }
    
    @objc func didTapClose(_ sender: Any) {
        dismiss(animated: true, completion: nil)
    }
}