class ViewController: UIViewController{
    override func viewWillAppear(_ animated: Bool) {
        // ...

        webView.delegate = self
    }
}

extension ViewController: UIWebViewDelegate{
    func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebView.NavigationType) -> Bool {

        // Important check for external suffix
        if let url = request.url, url.absoluteString.hasSuffix("#HKexternal") {
            HelaPayLinkHandler().handleHelaPayLink(url)
            return false
        }
        else{
            return true;
        }

    }
}

class ViewController: UIViewController{
    override func viewWillAppear(_ animated: Bool) {
        // ...

        webView.navigationDelegate = self
    }
}

extension ViewController: WKNavigationDelegate{
    func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
        
        // Important check for external suffix
        if let url = navigationAction.request.url, url.absoluteString.hasSuffix("#HKexternal") {
            HelaPayLinkHandler().handleHelaPayLink(url)
            decisionHandler(.cancel)
        }
        else{
            decisionHandler(.allow)
        }
    }
}