tanstaafl wrote:https://bugzilla.mozilla.org/show_bug.cgi?id=1310389 is a meta-bug to track OAuth support. Using that I found https://bugzilla.mozilla.org/show_bug.cgi?id=1310384 (Add OAuth2 support for AOL mail accounts) which is closed, stating it was implemented in version 63 (which is not a production release).
The 68.0 release notes mention "OAuth2 authentication for Yandex" but nothing about AOL. The 68.5.0 release notes mention adding "Support for OAuth 2.0 authentication for POP3 accounts". The 78.4.0 release notes has "Yahoo and AOL mail users using password authentication will be migrated to OAuth2".
I suspect there is no AOL POP support in Thunderbird due to AOL not implementing it on the server. Sometimes its not worth fighting City Hall. I suggest you consider switching to a IMAP account. You can disable some of its optional features to make it act more like a POP account. Just remember that you can't count on the mbox files like you can with a POP account, they can be modified/deleted when Thunderbird synchs the local and remote folders. That doesn't mean you can't use them to make a backup, it means you can only rely upon a copy of those mbox files.
All right. I think I might go with the unique app password if I have to, rather than switch to IMAP, but it's good to know that the IMAP option is possible, if nothing else works for me.
Thanks again for the assistance, and thanks to sfhowes as well.