In vacancies for Frontend, they write in the requirements “knowledge of the REST API”, why?

Question

Frontend

In vacancies for Frontend developers, they write in the requirements "knowledge of the REST API". Maybe I don’t understand something, but why does the front need to know the REST API?

Answer 1

Well, let's say the backend communicates with the frontend through the REST API, and you are like this - I don't know him, let's redo everything.
Need to know.