Generate documentation is not available for one of my projects

Hi,

I have a REST project where I created the APIs manually by adding resources to it and for this specific project I don't seem to have the option to Generate documentation available:

Also, not sure if this is related but I can't seem to have the ability to infer a schema for the REST requests belonging to this project.

 

Is this a normal thing for projects that are not created from an API definition?