ios WebView Transparent background

WebView.swift

class WebView {
    let webView: WKWebView = {
        let webView = WKWebView()
        webView.translatesAutoresizingMaskIntoConstraints = false
        webView.alpha = 1
        webView.isOpaque = false
        return webView
    }()
    
    override func viewDidLoad() {
      self.view.backgroundColor = #colorLiteral(red: 0.180518508, green: 0.187897712, blue: 0.196665138, alpha: 1)
      let myURL = URL(string:"http://www.yaminokishi.com")
      let myRequest = URLRequest(url: url)
      webView.load(myRequest)
      
      view.addSubview(webView)
      
      NSLayoutConstraint.activate([
            webView.topAnchor.constraint(equalTo: view.layoutMarginsGuide.topAnchor, constant: -10),
            webView.widthAnchor.constraint(equalTo: view.widthAnchor),
            webView.bottomAnchor.constraint(equalTo: view.layoutMarginsGuide.bottomAnchor, constant: -10),
      ])
    }
    
    func webViewDidFinishLoad(_ webView: WKWebView) {
        webView.backgroundColor = UIColor.clear
        webView.scrollView.backgroundColor = UIColor.clear
        for subview in webView.subviews {
            subview.backgroundColor = UIColor.clear
        }
        UIView.animate(withDuration: 0.5, animations: {
            self.webView.alpha = 1
        })
    }
}