Flutter Flow Builder Throwing Seemingly Unrelated Error

I have the following Flutter flow using flow_builder:

import 'package:flow_builder/flow_builder.dart';
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:myaccounts/menu_drawer.dart';






// FLOW

class NewAccountFlow extends StatelessWidget {
  static Route<Account> route() {
    return MaterialPageRoute(builder: (_) => NewAccountFlow());
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: FlowBuilder<Account>(
        state: const Account(),
        onGeneratePages: (Account, pages) {
          return [
            MaterialPage(child: NameAccountForm()),
            if (Account.name != null) MaterialPage(child: EnterAccountForm()),
          ];
        },
      ),
    );
  }
}



// STATE

class Account {
  const Account({
    this.name,

  });

  final String? name;



  Account copyWith ({String? name}) {
    return Account(
      name: name ?? this.name,
    );
  }
}



// FORMS

class NameAccountForm extends HookWidget {
  @override
  Widget build(BuildContext context) {
    final _name = useState<String>('Test');

    return Scaffold(
      appBar: AppBar(title: const Text('My Accounts')),
      drawer: MenuDrawer(),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          TextField(
            autofocus: true,
            onChanged: (value) => _name.value = value,
            decoration: InputDecoration(
              labelText: 'Account Name',
              hintText: 'Enter a name for your account',
            ),
          ),
          const SizedBox(height: 24.0),
          RaisedButton(
            child: const Text('Continue'),
            onPressed: () {
              if (_name.value.isNotEmpty) {
                context.flow<Account>().update((info) => info.copyWith(name: _name.value));
              }
            },
          )
        ],
      ),
    );
  }
}

class AccountValueField extends StatelessWidget {
  const AccountValueField({required this.place, Key? key}) : super(key: key);

  final String place;

  @override
  Widget build(BuildContext context) {
    return Padding(
      child: TextFormField(
        decoration: InputDecoration(
          border: OutlineInputBorder(),
          hintText: place,
          contentPadding: const EdgeInsets.symmetric(vertical: 6, horizontal: 10),
          isDense: true,
        ),
        //style: TextStyle(
        //  fontSize: 14,
        //  height: 1,
        //),
      ),
      padding: EdgeInsets.symmetric(horizontal: 8, vertical: 5),
    );

  }
}

class EnterAccountForm extends HookWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('My Accounts')),
      drawer: MenuDrawer(),
      body: Column(
        children: [

          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Padding(
                child: const Text('Enter your details:', style: const TextStyle(fontWeight: FontWeight.bold)),
                padding: EdgeInsets.symmetric(vertical: 8),
              )
            ]
          ),

          Row(
            children: [
              Expanded(child: Column(
                children: [
                  AccountValueField(place: '1'),

                ]
              )),

              Expanded(child: Column(
                children: [
                  AccountValueField(place: '2'),
                ]
              )),
            ]
          ),

          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 2),
                child: ElevatedButton(
                  onPressed: () {


                  },
                  child: const Text('Save'),
                ),
              ),
            ]
          ),

        ]
      )
    );
  }
}

which keeps throwing this error:

/usr/local/Caskroom/flutter/2.10.5/flutter/.pub-cache/hosted/pub.dartlang.org/flow_builder-0.0.7/lib/flow_builder.dart:367:36: Error: Method 'handlePopRoute' cannot be called on 'WidgetsBinding?'
because it is potentially null.
 - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('/usr/local/Caskroom/flutter/2.10.5/flutter/packages/flutter/lib/src/widgets/binding.dart').
Try calling using ?. instead.
    return WidgetsBinding.instance.handlePopRoute();
                                   ^^^^^^^^^^^^^^
/usr/local/Caskroom/flutter/2.10.5/flutter/.pub-cache/hosted/pub.dartlang.org/flow_builder-0.0.7/lib/flow_builder.dart:372:38: Error: Method 'handlePushRoute' cannot be called on 'WidgetsBinding?'
because it is potentially null.
 - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('/usr/local/Caskroom/flutter/2.10.5/flutter/packages/flutter/lib/src/widgets/binding.dart').
Try calling using ?. instead.
      return WidgetsBinding.instance.handlePushRoute(arguments);
                                     ^^^^^^^^^^^^^^^

I'm not sure where this error is coming from. Any help is appreciated.