After gmail recently greeted my mutt/IMAP request (which had worked perfectly for over a decade!) with "login failed", i've embarked upon the slow winding road to getting mutt to use OAuth2, or is it OAUTHBEARER?, for gmail. Out of a dozen or so hints spanning the last couple of years (many which depend on having python2 still around), i'd humbly promote these links to best hints:
[1] http://www.dcs.gla.ac.uk/~jacobd/posts/2022/03/configure-mut...
[2] https://www.reddit.com/r/backtickbot/comments/kyuq11/httpsnp...
Please post any better sites you discover. It really is an overly server specific mess.