These are the examples I used when working through the Educative course Intermediate Redux with Redux Toolkit, by Ohans Emmanuel. In short, it shows how to go from regular Redux usage with React to using Redux Toolkit, which removes a lot of boilerplate to make working with Redux easier.
The first example app, Cat Mood, is a very simple app that has a single state variable, updating it with a Redux Toolkit slice.
The second example app, TweetFind,
shows how to fetch data from an API by making asynchronous requests using createAsyncThunk.