Documentation API Rest C++

Hello people. I have a Rest API ready, and needed to do the documentation, so that it becomes automatic, the problem is that is in C ++ language. I've been researching, and it looks like I should use the Oatpp framework. I tried to do that, but due to lack of experience, I couldn't.
What would be the best way to document this API in C ++ so that it is automatic?
Has anyone documented a Rest C ++ API and could they help me?