Basically, I have been looking at a facebook integration to invite facebook friends specifically, using the facebook feature "game request" in the form of invite. It is a feature that exists in the facebook API, but I've been unable to understand if I would be able to use it with Playfab/FB integration.
The feature in question is explained here: https://developers.facebook.com/docs/games/services/gamerequests#invites
I found no other threads in forums that specifically deals with this feature in the scope of Playfab.