AutoSSL is for Letsencrypt certificates.
If you have already a Comodo Certificate, supposedly you must put the (file with the) cert in the "/etc/pki/tls/certs/" and put the key in "/etc/pki/tls/private/", and access CWP -> Webserver Settings -> Tab "Install From Server", and choose the file certificate, and user and the domain, and click in install.
Regards,
Netino