I have a domain containing source: build.xyz.com. With server IP xxx.xxx.xxx.xx
Users enter their domain name: yourdomainname.com in the backend and it is saved to the DB.

Users have a domain name: yourdomainname.com. They can access their domain management with records.
So how will they create records so that when they access: yourdomainname.com it will run data of: build.xyz.com (note that at this time the domain name on the browser will still be: yourdomainname.com)

I still don’t understand the operating mechanism. I hope for help. Thank you