How to use RestorableChangeNotifier (flutter)

I'm using Provider and a ChangeNotifier to access some data across multiple screens in my app. I'm now wanting to implement restoration, so that even if that app dies in the background the user will come back to the same page with the same data. I have managed to make the app go back to the same page, but I can't figure out how to implement a restorable version of my ChangeNotifier. I found a RestorableChangeNotifier class on the Flutter API but am struggling to use it. I've put a simple code below that demonstrates the issue that I'm trying to achieve - any help would be appreciated!

Super simplified example

Class that uses ChangeNotifier, that stores the data:

class ItemClass extends ChangeNotifier {
  final List<String> _itemNames = [];
  List<String> get itemNames => _itemNames;

  void addItem(String newItem) {
    _itemNames.add(newItem);
    notifyListeners();
  }
}

Top level widget with ChangeNotifierProvider:

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

  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
      create: (context) => ItemClass(),
      child: const MaterialApp(
        home: HomeScreen(),
        restorationScopeId: 'root',
      ),
    );
  }
}

The screen I want to be at, showing the info from the ItemClass:

class Screen1 extends StatefulWidget {
  const Screen1({Key? key}) : super(key: key);

  @override
  State<Screen1> createState() => _Screen1State();
}

class _Screen1State extends State<Screen1> {
  final TextEditingController _textEditingController = TextEditingController();

  @override
  void dispose() {
    _textEditingController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    ItemClass itemClass = context.watch<ItemClass>();
    return Scaffold(
        appBar: AppBar(),
        body: Center(
            child: Column(
          children: [
            Text('Items: ${itemClass.itemNames}'),
            TextField(
              controller: _textEditingController,
            ),
            TextButton(
                child: const Text('Add item'),
                onPressed: () =>
                    itemClass.addItem(_textEditingController.text)),
          ],
        )));
  }
}

I don't know where or how to implement the restoration for this ItemClass.