How to create a 5th level sub-domain on Digital Ocean?

Question

Domain Name System

There are 2 droplets on DO. On one site and it works already. Let's say the domain for the 1st is my_domain.com. On the 2nd - without a domain, just an ftp server.
How can I now make the 2nd droplet available at: aaa.bbb.ccc.my_domain.com? Where is it generally configured and how? Yes, in the DO panel, how to do this for the 5th level domain: aaa.bbb.ccc.my_domain.com?

Answer 1

This is done using dns.