No email accounts when I revert from Outlook to Legacy Outlook

Have been using the current free Outlook for Mac Ver 16.86 for about a year. I wanted to start using Spamsieve again (used it with Airmail earlier) so I started the process given in the directions on this site (I just purchased the 3.0 upgrade). When I reverted to legacy no email accounts came through from the current Outlook. When I to tried to add them Microsoft wanted me to buy their 365 subscription which I do not need or want. Could not get through this to add email accounts. It just bounces me to buy 365. How do I proceed? I thought it was just revert to legacy outlook and setup the settings.

I think the free version of Outlook only supports the new, limited feature set.