I have to use an API for my android app without any documentation. Before in my work I always had documentation, so this is a new situation for me. Backend developers said their api supports option requests. How to send option request? Using browser or what? And how to find out what I should put in POST requests' bodies? Thanks for your help in advance!
You can issue an OPTIONS request (which is an HTTP method like GET or POST) like so with, say, curl:
curl -X OPTIONS http://example.org -i
or Postman.
However, OPTIONS is designed only to reply with the methods a particular endpoint accepts: I can do GET and POST. It would be rather irregular for it to respond with an expected data structure, but nothing is impossible.