Someone trying to hack my Apple password using security questions

I keep these emails everyday, someone is trying to hack my account clearly:

“We were unable to reset the password for your Apple Account (xxx@gmail.com) because there were too many unsuccessful attempts to answer your security questions. To protect the security of your account, you will not be able to reset your password for the next eight hours.”

when I go into my Apple settings I see that I have 2 factor authentication enabled but I don’t see anything related to security questions. (I want to change them)

how exactly are these hackers trying to answer these security questions ? Do I need to be concerned ?