Joke Collection Website - Blessing messages - If device authentication is not enabled on site b, will there be a prompt when someone else logs in to my account?

If device authentication is not enabled on site b, will there be a prompt when someone else logs in to my account?

Yes.

If the other party has logged in on the other party's device and remembered the password, the other party can log in directly without verification. If you do not remember the password, SMS verification is required. SMS verification will be sent to your mobile phone, and you will receive the message. If he remembers the password and account, he can log in directly without going through you. Then he can see everything on your site B.