To use React Query throughout your application you'll need to import and create a new instance of QueryClient and pass that to the QueryClientProvider component in the root of your app.
The lesson description lacks the link to the API repository, and the one I found in Tomasz's repositories doesn't work with this course code: https://github.com/ducin/egghead-typescript
hi Andre, thanks for noticing! That's the repo: https://github.com/ducin/egghead-react-query. We'll link it in the course description.