title: registering response from inappwebview flutter
body: <p>I am confused with inAppWebview. I need to get response from the webview when user presses the button and some json data sent to the app. My english is not enough to get which method catches that data from the webview? So, far I only have the widget now...</p>
  <pre><code>@override
  Widget build(BuildContext context) {
  String url = 'https://test.hipay.mn/payment?checkoutId=' + widget.checkoutId
      + '&amp;shopperResultUrl=' + widget.shopperResultUrl
      + '&amp;shopperCancelUrl=' + widget.shopperCancelUrl
      + '&amp;lang=' + widget.lang;
  return Scaffold(
    appBar: AppBar(
      title: Text(Languages.of(context)!.appName),
    ),
    body: Stack(
        children: [
          InAppWebView(
              key: webViewKey,
              initialUrlRequest: URLRequest(url: Uri.parse(url)),
              initialOptions: options,
              onWebViewCreated: (controller) {
                webViewController = controller;
                webViewController!.addJavaScriptHandler(handlerName: 
   'myHandlerName',
                    callback: (args) {
                  debugPrint(args.toString());
                });
                },
  
  ),
        ]),
  );
  }
  </code></pre>
  <p>help appreciated. I cant seem to find enough tutorials on inappwebview....
  I need to register <a href="https://i.stack.imgur.com/88CFx.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/88CFx.jpg" alt="this data" /></a> sent from the server, however I am stuck on how to get it and register the output, if the payment is successful.</p>