如何在WKWebView中获取令牌？

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)
        
        let url = URL(string: "https://example.com")!
        let request = URLRequest(url: url)
        webView.load(request)
    }
    
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        // 判断当前加载的网页是否包含令牌信息
        if let url = webView.url, url.host == "example.com" {
            // 执行JavaScript代码，提取令牌
            webView.evaluateJavaScript("document.getElementById('token').value") { (result, error) in
                if let token = result as? String {
                    // 获取到令牌后的处理逻辑
                    self.handleToken(token)
                }
            }
        }
    }
    
    func handleToken(_ token: String) {
        // 处理获取到的令牌
        // 可以将令牌保存在本地，或者发送到服务器进行验证等操作
        print("Token: \(token)")
    }
}