Soneone hacked my account

Hello,
I’ve god message from Mozilla that someone “hacked” my account on seznam.cz from Windows 10 Chrome. I am Linux user. I was not online yesterday. So when I click on the link to change password I cannot do it because there is login screen.

Your Mozilla account was used to sign in

Chrome on Windows 10
Sunday, Apr 7, 2024
9:30:22 PM (CEST)

So someone changed the password but I cannot change it anyway. Did the person changed the email too? I don’t remember the account name or id.