Providing clients with custom comments, looking for solution.

Hi there every one.

I have a small service for growing followers for my clients. I am trying to figure out how to provide clients with a way to write their own Instagram Comments without leaving my site. I know there are many re-sellers for various custom comments, but I guess I am lacking technical background to set this up.

Has anyone ever done this before? Any ideas and suggestions? I would be willing to pay for solution for this issue.