To add CNAME to your account, please go to Settings page and find Custom CNAME option part:
- Click on Add New Cname button
- Enter something unique for ID (like MyCname or siteNameCname)
- Enter actual CNAME as URL (this requires you setup this URL as DNS CNAME RECORD at your domain provider)
- Click on Create Cname button (this will verify your URL and DNS record, and will install SSL certificate if needed) to create Custom CNAME.
Detailed instructions for creation of DNS CNAME RECORD is here https://publit.io/community/blog/custom-cname-cdn-for-media-files-urls-at-publitio