The Adobe Acrobat for Microsoft Teams is a useful add on for Teams but, once added to a Team, the features are only available in public channels, not in private. Although Teams does treat public and private channels differently, it should be possible to develop a plug in that works in both cases. If this is not possible, this limitation should be fully documented. At this time, in my experience, neither is the case. I am working with customer service and hope to find that there is an issue with my installation (and not with the app), but no troubleshooting has been suggested at this time.