Problem certificatre ssl

[ArP22RC]

@Admin

Reminder: “www” Subdomains Are Not Covered

Due to the way wildcard SSL certificates work, subdomains like www.example.ct.ws are not covered by the system-wide SSL certificate. Only direct subdomains (e.g., example.ct.ws) are supported.

If your site uses a www. subdomain, we recommend switching to the non-www version to ensure your visitors stay protected with HTTPS.

Existing custom certificates for www subdomains will continue to work until they expire. After that, they cannot be renewed.

How do I switch to the non-www version?
Do I have to pay?
Thanks