zextras team - how do you send files?

Hi, I have purchased some team pro licenses to try out. I've enabled pro features on several users. And I'm trying to work out how to send files to them? I can't see any extra buttons (only info and video chat buttons) in the chat pane. Drag and drop doesn't seem to work either.

The documentation mentions file sending but doesn't say how to do it.

Regards,