SharePoint tab missing in "Add a tab" Screen

Hi there,

One of our users have requested we enable the ability to add the SharePoint tab to Teams as described here - https://support.microsoft.com/en-us/office/add-a-sharepoint-page-or-list-to-a-channel-in-teams-131edef1-455f-4c67-a8ce-efa2ebf25f0b  Here are the options we see - 

I have turned off all 3rd part apps, but since this is a Microsoft app I would expect that it would show up here? What am I missing?

Thanks,

Aled.