How to use the comment and bookmark features in Integrity?

I added in my viewset the comment feature but I don't knwo how to use it. I didn't find any information in help but there was another useful feature named bookmark.

I wanted to use it as well but I don't understand how to activate it. When I highlight a text and I want to use "properties" in drop-down menu, this feature is greyed.

Any recommendations:

     - to use the comments

     - to activate the bookmark feature