Hi there. My main domain is hosted by a conventional shared hosting service, with cPanel access, but a subdomain of it is hosted by Google's Blogger service (which only gives me the option of a toggle for "HTTPS availability" (I believe it does use Let's Encrypt). I know questions have been asked before about subdomains on separate host servers, but the answers are way over my head. I am unfortunately a total noob as far as SSL, and need someone to walk me through the process of getting both the main domain and the separately-hosted subdomain HTTPS-ready.
I understand that I can issue Let's Encrypt certificates for the main domain through my cPanel. The Blogger subdomain, which is represented in my cPanel DNS settings with a CNAME record, is not among the subdomains that the cPanel Let's Encrypt applet offers to issue a certificate for.
On the Blogger end, toggling "HTTPS availability" to "on" fails, with the error message "You have not been authorized to use this domain." The help file contains this piece of (possibly relevant?) advice, but I don't know what it means:
Important: If you use CAA Records on your custom domain, add a record for letsencrypt.org, or Blogger won't create or renew your SSL certificate.
How can I get the Blogger-hosted subdomain's SSL working, and is there something specific I need to do (or avoid doing) while setting up SSL for the main domain on the other host's cPanel?
Thank you so much for the help.