The.com Sites takes the frustration out of custom domains.
Step 1 - Click the site settings icon to open the domain modal
Step 2 - Add the domain you want to connect (make sure to always add www. or other subdomains in front of your URL)
Step 3 - Click Validate Domain, after a few seconds you will be given two sets of CNAME records. These are the only two records you need to add to your registrar (where you bought your domain like godaddy or namecheap) Here are two resources on how to add CNAME records to a few popular registrars:
Step 4 - Click I've Added The Records. You’re done! After about 10 minutes you should see your live domain connected to the site (sometimes it can take up to 24 hours)
If you are using CloudFlare and your domain connection failed, please add this CAA record on your DNS records and try again.
Below is a quick video of the process