Background info: my hosting is a shared cPanel unix hosting account at GoDaddy. GoDaddy is not enthusiastic about Let’s Encrypt, so one has to do the Let’s Encrypt process manually, as well as the renewals. I used zerossl to get the certificate and successfully installed it using cPanel. The URL for which the certificate was issued is dgelsci.com
Problem (realized after a few days): I ONLY got the certificate for the non-www domain. I did NOT realize the importance of getting the certificate for both the www and non-www domain names until I used the www-based URL to get to my site. When the www is included in the URL, there is an error message about the site and the certificate not being properly configured (Note: I have figured out an htaccess-based workaround to my problem, despite the workaround, I would like to know the process to fix non-www issue).
Question: Can I add the www URL to the already issued certificate for the non-www? If so, how can this be done using the manual process? Or, is there another way to fix this?