Importing pdf attachment from a reference manager?

This may be explained somewhere, but I could not find out where. I am trying to import a pdf from my reference manager (currently trying out Bookends) and I cannot find out how to import it into my Scrivener Reference files. Is there a way to do this?

Hou should post this question in Technical Support, not in here. This part of the forum is for describing how you use Scrivener.

Thanks, sorry!