How to integrate swagger with spring cloud function

I have one spring boot application having three spring cloud function which I am able to execute via postman or curl successfully .Now my next step is to add swagger documentation for the same. I have followed all configuration that we do to add swagger with normal spring boot project. And it is up and running but problem is that my functions URL are not listed in swagger since Request Mapping or API operations annotations are not getting picked up maybe those are just functions not a controller that's y. So if someone could help how to integrate so i can document all cloud functions that I am creating.