If I have a domain name, can I use it for gmod server?

so I have 1 domain name on www.domain.com which is www.arleitiss.com
Can I somehow make it to work like:
WHen you in console type connect gm.arleitiss.com player woudl connect to my server?

If your subdomain (gm) is DNS’d to your servers IP Address then yes it will work, you can use the following:

and so forth.

You want to make an “A” record for the domain.