We’ve heard reports that the Microsoft Teams Meeting Add-in for Outlook on Windows does not show up for some users who have installed the desktop app. There are several reasons why the add-in may no...
Updated Nov 09, 2023
Version 2.0
Blog Post
You are most likely being restricted at a tenant level by the admin, as mentioned before. You have no choice in the matter, to be blunt. If you make registry changes and when the Teams and Outlook client relaunch or on the next reboot, these settings are reinstated to the defaults, that the admin has set. How SfB and Teams interactive with Outlook (your options and addons) are down to the Mode selected by the admin. In short, if this is a corporately issued device, then your only option is speak with your local Support Team or Local M365 Admin if you want this changed.
See the option below, I selected the most likely option in your case based on what you have said.
Migration and interoperability guidance for organizations using Teams together with Skype for Business - Island
https://docs.microsoft.com/en-US/MicrosoftTeams/migration-interop-guidance-for-teams-with-skype?WT.mc_id=TeamsAdminCenterCSH#coexistence-modes