Is a request body always needed when using the POST method?

Question

API

Is a request body always needed when using the POST method?
In general, is it possible to use the POST method and receive some data on the server side without a request body?
And how can you understand which request body you need to use, is it possible to compose a request body yourself without knowing what data should be transmitted to the server?

Answer 1

In case there is no request body, there is a GET method