I have searched everywhere but cannot find any way to remove this Outlook addin. It is a very annoying and keep on sending update alerts every 5 minutes.
I have contacted the MS Office Support and they said the following:
Navigate to the ribbon under 'Home' tab > click on 'Get add-ins' option > click on 'manage add-ins/My Add-ins' option in the left column > try removing the Add-ins that you would like to remove.
But there is no option called "Get add-ins". Attaching the image:
I tried searching for anything with Add-in in every menu and every ribbon and still didn't get any answer.
MS Office support didn't reply back after this and because probably even they don't know how to fix it.
Best Answer
I found it! The zoom plug-in / add-in is not provided by the Microsoft store, rather installed by zoom itself, so you won't find it in the Microsoft store > my add-ins area. If you go to finder > applications, you will see a folder called 'Zoom plugin for Outlook', in that folder is an uninstall icon. Close outlook, uninstall, and voila....zoom gone!
This has been especially important since the zoom client no longer works in macOS Catalina, so it's useless to keep it in outlook.