let webView = WKWebView()
webView.navigationDelegate = self

let url = URL(string: "https://postcode.pocketlesson.io")!
webView.load(URLRequest(url: url))

func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
  switch navigationAction.request.url?.scheme {
  case "postcode":
    if let urlString = navigationAction.request.url?.absoluteString {
      let components = URLComponents(string: urlString)
      let address = components?.queryItems?.first { $0.name == "address" }?.value
      let zonecode = components?.queryItems?.first { $0.name == "zonecode" }?.value
      print(address) // e.g. 서울 강남구 역삼로 180
      print(zonecode) // e.g. 06248
    }
    decisionHandler(.cancel)

  default:
    decisionHandler(.allow)
  }
}

let webView = WKWebView()
webView.configuration.userContentController.add(PostcodeHandler(), name: "postcode")

let url = URL(string: "https://postcode.pocketlesson.io")!
webView.load(URLRequest(url: url))

class PostcodeHandler: NSObject, WKScriptMessageHandler {
  func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
    guard let data = message.body as? [String: Any] else { return }
    let address = data["address"] as? String // e.g. 서울 강남구 역삼로 180
    let zoneCode = data["zonecode"] as? String // e.g. 06248
  }
}