Understanding Middleware in Redux Toolkit

Every action passes through a row of functions before it reaches a reducer, and configureStore has already installed several of them. These functions are called middleware. Each one receives the action, may do something with it, and decides whether to pass it to the next function in the row. A middleware can log an action, change it, block it, or start other work, all without any change to your reducers.

The Middleware You Already Have

createAsyncThunk worked in the previous lesson because configureStore includes the thunk middleware by default