在iOS WKWebView中单击带有URL的Whatsapp方案时出现不支持的URL错误

import UIKit
import WebKit

class ViewController: UIViewController, WKNavigationDelegate {
    var webView: WKWebView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let configuration = WKWebViewConfiguration()
        webView = WKWebView(frame: view.bounds, configuration: configuration)
        webView.navigationDelegate = self
        view.addSubview(webView)
        
        // 加载网页
        if let url = URL(string: "https://example.com") {
            let request = URLRequest(url: url)
            webView.load(request)
        }
    }
    
    // WKNavigationDelegate方法
    func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
        if let url = navigationAction.request.url, url.scheme == "whatsapp" {
            // 使用UIApplication的openURL方法打开Whatsapp
            UIApplication.shared.open(url, options: [:], completionHandler: nil)
            decisionHandler(.cancel)
        } else {
            decisionHandler(.allow)
        }
    }
}