Issue with adding Upgrader pub.dev package into flutterflow

I am trying to use the upgrader package as my goal is to make it so that when a user accesses their app it will check that there is a new update and ask the user to update their app, but I am not sure how integrate this package within my app, can I do it by turning it into a custom widget?

https://pub.dev/packages/upgrader/install

// Automatic FlutterFlow imports
import '/backend/backend.dart';
import '/backend/schema/structs/index.dart';
import '/flutter_flow/flutter_flow_theme.dart';
import '/flutter_flow/flutter_flow_util.dart';
import '/custom_code/widgets/index.dart'; // Imports other custom widgets
import '/custom_code/actions/index.dart'; // Imports custom actions
import '/flutter_flow/custom_functions.dart'; // Imports custom functions
import 'package:flutter/material.dart';
// Begin custom widget code
// DO NOT REMOVE OR MODIFY THE CODE ABOVE!

import 'package:upgrader/upgrader.dart';

class Upgrader extends StatefulWidget {
  const Upgrader({
    Key? key,
    this.width,
    this.height,
  }) : super(key: key);

  final double? width;
  final double? height;

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

class _UpgraderState extends StatelessWidget {
  const _UpgraderState({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Upgrader Example',
      home: UpgradeAlert(
          child: Scaffold(
        appBar: AppBar(title: Text('Upgrader Example')),
        body: Center(child: Text('Checking...')),
      )),
    );
  }
}