This is done by authenticating to both environments, and only needs to be established one time.
All users should be able to do this without elevated system permissions. Installing/Enabling the add-in on your Office account – The one-time process for enabling the add-in from the 365 store.This document is broken into three parts: The Adobe Sign add-in allows a user to open any Word or PowerPoint file (5MB or under), and use that file as the basis for a new agreement.