But isn't that product ("Outlook Premium") closed off to new subscribers since 2017? (https://support.microsoft.com/en-us/office/outlook-com-premi... ) I also had a similar experience to the parent poster, i.e. MS support required transferring the domain to godaddy before one could use it for Outlook if using a consumer-focused O365 plan.

Oh. Color me corrected. That requirement honestly sounds insane.