How do I set up selling my domain for third-level domains?

Question

Domain Name System

There is suppose a domain - "domain.com". It is necessary to implement the possibility of selling or free setting up a domain to create a third level, so that a person who needs my domain can set up DNS for himself and use "site.domain.com" on his hosting.
How can this be implemented? Are there already ready-made solutions for this issue? Free or paid.
Still haven't found a solution.

Answer 1

You can use the service API on your site, where to delegate the domain. And create subdomains there or delegate them somewhere else.

Answer 2

It is enough to configure one DNS record "*.domain.com" -> yourIP.
Purchase interface - write the required one yourself or https://ru.wikipedia.org/wiki/%D0%A1%D1%80%D0%B0%D...
When buying a subdomain, create a file in /etc/nginx/conf.d / and `service nginx reload`