Option to add Zoom in MS Outlook Calendar meeting event has disappeared

[PleaseHelpZoom]

A while ago I set up MS Outlook so that when I create a meeting in my calendar, as well being able to use Teams, I had the option to click on Zoom and add that as the app for the meeting.
For some reason this option has recently disappeared from my Outlook Desktop calendar and I can not get it back.
It happened when I removed an obsolete account I had in the Outlook app. I have know idea why this would affect my default account, but it seems to have caused the Zoom option to disappear.

If I open Office 365 and view Outlook in Outlook Online, the Zoom option is still there and works fine, so for some reason it has only disappeared from the Desktop Version of Outlook.

(If I check in Outlook Online in My Add-Ins, I can see that Zoom is there, so I assume it should work).

Please note:

When I Googled this issue, some suggestion said to download:

Zoom Plugin for Microsoft Outlook

However, I tried this and it did not work.

Can anyone please help?