I was looking for a simple solution to link our FreePBX to Microsoft Teams. I found a simple solution that I liked so much, my company became a reseller. It’s on a per-user basis with nothing to install so companies can pick and choose which users they want to have access. You can also choose if you want to use Teams voicemail or your PBX’s.
We use this everyday and I’m very happy with it. If you need help with something like this, please let me know.