Give group owners an optional ability to toggle on 2 factor authentication to be activated on someone's account as a requirement to join a group.

Two many people are falling for those phishing links and this may encourage them to sign up for some form of 2 factor. Plus in some ways this may make it slightly more difficult (yes I know it may still be possible) for those who are doing those phishing links to even join random groups and trick those who aren't using common sense. Would be nice to see more actually using 2 factor.

This should be fully optional for the group owner to enforce and be part of the permissions for group roles. Also if this is added also include a message so the users knows if they try to join a group that requires it if they do not have it activated on why they can't join and how to activate it.