Subdomains get free SSL through AutoSSL just like main domains. First create the subdomain in cPanel > Domains (or Subdomains), then secure it:
- Make sure the subdomain's DNS resolves to your Toshost server.
- Open SSL/TLS Status, tick the subdomain, and click Run AutoSSL.
- Wait a few minutes, then confirm it shows a valid certificate.
Once secured, force HTTPS for that subdomain in Domains or via .htaccess in its document root. If you have a wildcard certificate for *.yourdomain.com, you can instead install it on the subdomain under Manage SSL sites. If AutoSSL won't cover the subdomain, check that DNS has propagated and there's no conflicting redirect, then open a ticket if needed.
