InAppWebView - How to enable download files in WebView

InAppWebViewOnDownloadStartExample.dart

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter_inappwebview/flutter_inappwebview.dart';
import 'package:flutter_downloader/flutter_downloader.dart';
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';

Future main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await FlutterDownloader.initialize(
      debug: true // optional: set false to disable printing logs to console
  );
  await Permission.storage.request();
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  InAppWebViewController _webViewController;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('InAppWebView Example'),
        ),
        body: Container(
            child: Column(children: <Widget>[
              Expanded(
                  child: InAppWebView(
                    initialUrl: "http://ovh.net/files/1Mio.dat",
                    initialOptions: InAppWebViewGroupOptions(
                      crossPlatform: InAppWebViewOptions(
                          debuggingEnabled: true,
                          useOnDownloadStart: true
                      ),
                    ),
                    onWebViewCreated: (InAppWebViewController controller) {
                      _webViewController = controller;
                    },
                    onDownloadStart: (controller, url) async {
                      print("onDownloadStart $url");
                      final taskId = await FlutterDownloader.enqueue(
                        url: url,
                        savedDir: (await getExternalStorageDirectory()).path,
                        showNotification: true, // show download progress in status bar (for Android)
                        openFileFromNotification: true, // click on notification to open downloaded file (for Android)
                      );
                    },
                  ))
            ])),
      ),
    );
  }
}

i am not able to download if my file is related to blob URL getting below error.

Update notification: {notificationId: 7, title: blob:
"COMPANY URL", status: RUNNING, progress: 0}
D/DownloadWorker( 5399): Update too frequently!!!!, but it is the final update, we should sleep a second to ensure the update call can be processed
D/DownloadWorker( 5399): Update notification: {notificationId: 7, title: blob: "COMPANY URL" status: FAILED, progress: -1}
W/System.err( 5399): java.net.MalformedURLException: unknown protocol: blob

@ranjan51 does this help you pichillilorenzo/flutter_inappwebview#2212 ?