Earlier quoted context omitted.
> always says "You will never be asked for this code" and everytime they ask for it. Yes, but the real meaning behind that phrase is "You will only be asked for this code by pages served by our domain name or a native app we published." It's unfortunate brevity.
Maybe it would be better to send a link. Then it can't be sent to the wrong domain. Of course you need to then educate people that they shouldn't trust the domain they land one and always immediately close the tab. Even if that tab says "Warning you have a fraud alert on your account. Click here to check your recent transactions"
The link may look similar or even appear identical, and still be under control of the scammer.
Similar to just not trusting incoming phone calls, you can't really trust incoming links via standard email, without some definitive way of validating the sender.