Hello Retrotel,
I have few questions, which can help in understanding the issue. So when you are trying to install it on your employee machine, Is it giving you any error? or it's installed successfully but not showing up in the Add ins? Did you try to run it as Admin because sometimes it requires special permission to install.
I am providing here a LINK from our Help Centre on Outlook Plug in Installation, you might find it useful. If you still have any problem, I would suggest you to call our support team, we would like to help you with that.
-Inder