Using Microsoft Teams on macOS, including installation, features, and compatibility
I tried every possible solution listed in all the pages of this chat and nothing worked. Randomly I logged into work on Monday and got this when opening teams. I had to uninstall and reinstall new teams twice before it would even open. Once I got it back up and running teams notification settings in Teams and on my Mac were both all turned off. I turned them all back on and now it is working.
Somewhere along the way it said that the teams sound driver or something like that was missing or damaged so not sure if this will work for someone else who doesn't get this pop-up up but it's worth a shot. Good luck!