Connection Not Secure with Custom Domain through Hover

I am trying to set up a custom domain for Obsidian publish through Hover, however when I access the site through that domain I get a message “Your connection is not private”. It is set up with a subdomain using a CNAME record to “publish-main.obsidian.md” as described in the instructions.

Hover only gives the options for Host Name, Target Name and TTL when setting up the DNS record.