requestCode method Null safety
Implementation
Future<String?> requestCode() async {
_code = null;
final urlParams = _constructUrlParams();
var webView = WebView(
initialUrl: '${_authorizationRequest.url}?$urlParams',
javascriptMode: JavascriptMode.unrestricted,
navigationDelegate: _navigationDelegate,
);
await _config.navigatorKey.currentState!.push(MaterialPageRoute(
builder: (context) => Scaffold(
body: SafeArea(child: webView),
)));
return _code;
}