How to open sites hosted on the local network (behind the router)?

Question

D-Link

Actually, the situation is this.
There is a CentOS server with VestaCP behind a D-Link DIR-320 router.
All ports are forwarded through the DMZ of the router itself, in principle, there seems to be no problems with this.
I can connect to the main site, which hangs on port 80 and is the name of the server.
From the local network, I open the site through the internal IP - 192.168.0.XXX and 192.168.0.XXX:80.
Also, I can open the main site from a remote location through an external IP, with and without port 80.
I can also connect to Vesta: locally with port 8083, from outside - via external IP and port 8083.
But here's the problem.
If I create a new site, let's say: subdomain.servername.loc, I can only open it from a remote location.
On the side of the NS server, there is an A record of my external IP.
And how can I access the same site from the local network?
Now the download just hangs and nothing happens.