Flutter: inAppWebview doesn't load initialUrl

You can copy paste run full code below
When InAppWebView load finish. you can directly call webView.loadUrl to change url
code snippet

InAppWebViewController webView;

onWebViewCreated: (InAppWebViewController controller) {
        webView = controller;
      },

webView.loadUrl(url: "https://flutter.dev/");

working demo

full code

import 'package:flutter/material.dart';
import 'package:flutter_inappwebview/flutter_inappwebview.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  InAppWebViewController webView;
  bool status;

  _changeUrl() {
    webView.loadUrl(url: "https://flutter.dev/");
  }

  Widget myPlayer(String url) {
    print('WebView con: $url');
    return InAppWebView(
      initialUrl: url,
      initialHeaders: {},
      initialOptions: InAppWebViewGroupOptions(
        crossPlatform: InAppWebViewOptions(
          debuggingEnabled: true,
        ),
      ),
      onWebViewCreated: (InAppWebViewController controller) {
        webView = controller;
      },
      onLoadStart: (InAppWebViewController controller, String url) {
        status = false;
      },
      onLoadStop: (InAppWebViewController controller, String url) {
        status = true;
      },
      onWindowFocus: (controller) => {},
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: myPlayer("https://pub.dev/"),
      floatingActionButton: FloatingActionButton(
        onPressed: _changeUrl,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}