Issue with accepting challenge via RESTapi

I have a problem with accepting challenge via RESTapi. Despite the fact that I have received the challenge and I can get it id by selecting field id from the first element of the list results from GET response. When accepting it by POST{here_is_my_challenge_id}/accept
I got 404 HTTP “error”: “Challenge does not exist”, but it clearly does. I would appreciate any help on this issue. Also I have somewhat unrelated question. Is it possible to use REST api for accepting removed stones?

The cause of problem was wrong url.
Correct url is{here_is_my_challenge_id}/accept

Yeah, some of the docs don’t have the right resource listed, or are very ambiguous about it.