How to configure go back button in Browser for Flutter Web App

Question

I'm not asking about webview. This is about Flutter web app. I need to go back to a specific page when user press back button which is inbuilt in browser.

Any guessing ?

I'm getting this error when I press back button

Error: Assertion failed: org-dartlang- 
    sdk:///flutter_web_sdk/lib/_engine/engine/history.dart:110:14 
    _userProvidedRouteName != null
    is not true
        at Object.throw_ [as throw] (http://localhost:8300/dart_sdk.js:4770:11)
        at Object.assertFailed (http://localhost:8300/dart_sdk.js:4721:15)

Answer 1

In case if you don't want to navigate to a new page

    @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () async => true,
      child: Scaffold(

        key: _scaffold,
        backgroundColor: Colors.indigo,
        body: Center(
          child: Container(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                registerForm(),
                registerBtn(),
                SizedBox(height: 30,),
                _buildSignInButton()
              ],
            ),
          ),
        ),
      ),
    );
  }