They seized some of the domains here is the official statment.

Dear Z-Librarians, Since one of our main domains was seized, we are experiencing some technical issues. Our team is already working to restore functionality. There may be delays in crediting donations, but don’t worry - the system will automatically credit them and upgrade your accounts to premium status as soon as possible. Please pay attention to possible fraudulent activities on behalf of our library, and remember that our site does not offer lifetime premium status. The website is still available via the links below:

• singlelogin.re
• singlelogin.rs

We are currently working on getting our support team back up, so they can reply to all your messages. Thank you for your understanding and patience ❤️