WKWebView

// In the MTR view controller

let vc = storyboard.instantiateViewController(withIdentifier: "WebViewController")
self.navigationController?.pushViewController(vc, animated: true)


// Web View Controller, assuming a matching view controller in the storyboard

class WebViewController: UIViewController {

    @IBOutlet weak var webView = WKWebView()

    override func viewDidLoad() {
        super.viewDidLoad()

        let url = URL(string: "https://whatever")
        let request = URLRequest(url: url)

        webView.navigationDelegate = self
        webView.load(request)
        
        // If loading a PDF from disk
        // webView.loadFileURL(url, allowingReadAccessTo: url)
    }
}

extension WebViewController: WKNavigationDelegate {

    func webView(_ webView: WKWebView, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        completionHandler(.performDefaultHandling, nil)
    }
}