How to off two factor authentication

Once you have enabled 2-factor authentication you have 2 weeks in which you can turn it off, by using the link in the email you got when you enabled it. After two weeks you can't turn it off.

Once it's been activated over 14 days it can't be turned off.

No.

In latest version of iPhone once you enable 2FA you can't disable it and it will be permanent , nothing to do with 14 day time limit and there is no selection button to turn it off .