I have only been offered to set up 2FA through SMS or occasionally the authenticator. It never works with the authenticator apps and the SMS is a non starter because if I use my Canadian number it's of no use to me when travelling with my UK sim and vice versa. So I have just ignored the prompt and email every time and refreshed and then the app/website just allows me to proceed as normal. Until there is a way for this nonsense to just work off of the facial id or email I have no intention of setting it up. If that means BA will just lock me out permanently then that's their loss of revenue. Never have had these issues setting up 2FA on any other accounts like banking etc.