How to enable OAuth2 with Apple icloud email

I recently moved from Microsoft Outlook email to Apple icloud email. icloud allows you to create an application-specific password, which I did for email. It works; I can login to email on Thunderbird using my (impossible to remember long) password automatically generated by Apple. I switched the Thunderbird server settings to OAuth, but unlike with Outlook, there was no popup saying a restart of Tbird is required. When I quit Tbird and restarted, it did not prompt for a pw, but neither did it get any new messages. (I sent new messages from another email service to verify.) I also noticed that OAuth2 was not an available option for the outgoing server, as it was with Outlook. Does OAuth2 not work with icloud email? There appears to be no way to change the app-specific icloud pw in Apple, but I will take that up with Apple. Perhaps the workaround is to use the Tbird saved pw feature?