See New Features Rolling Out Soon
Go to Settings.
Click Custom domains.
Click Start setup.
Select an option below and follow the additional steps.
Note: You can connect up to five custom domains to one site. It may take up to 48 hours for changes to your domain to become visible on the Internet.
See Custom URL instructions for GoDaddy
For G Suites accounts read more here and see Steegle's instructions here .
For domains registered with Google Domains click here. Note that when a domain is registered at Google Domains, domain ownership proof is automatic. See also Using Workspace account.
Note: This website is now mapped to: https://new.k8oms.net and https://www.k8oms.net/ and https://www.k8oms.page
If you want a domain link that goes to a particular page in your site, use forwarding instead of mapping. For instance rate.k8oms.net
I did this by setting up forwarding in my domain panel to forward the subdomain 'rate' to a page in the site. See the image below to see how I did it in Godaddy.
New Google sites are automatically secure (https) at the native Google URL and at the mapped domain, so it is not necessary to purchase a SSL certificate. If necessary, use this procedure to refresh the certificate: Remove the custom URL from your site, wait about 15 minutes then add the custom URL again and that will generate a new SSL certificate.