Question about flutter inappwebview!

I processed Schema by following code below in flutter_webview.

navigationDelegate: (NavigationRequest request) {
  if (request.url.contains("tel:")) {
    launch(request.url);
    return NavigationDecision.prevent;
  }else if (request.url.contains("kakaolink:")) {
    launch(request.url);
    return NavigationDecision.prevent;
  } else {
    return NavigationDecision.navigate;
  }
},

How should I change this code above in flutter_inappwebview?

Please helpe me on this!! I beg your generosity. Thank you in advance!!