You'll be taken to Settings -> Passwords, where you may need to manually select the correct account to add the verification code.

You can just autofill the verification code from your keyboard -- but you can't do it from just any third-party email application. If you want to autofill email verification codes on iOS 17, here ...

iOS 17 is adding a new feature that will allow users to have verification codes automatically deleted in Messages and Mail.

Mac 911 How to find alternatives for verification codes when roaming SMS remains a weak point in verifying logins and may be unavailable to you while outside your home country or region. Mac 911 ...