What does dvrhost.com mean when setting up a DVR broadcast?

Question

Windows

I set up a broadcast from a DVR with the ability to connect from anywhere in the world. We bought a static IP from the provider, set up the registrar according to the instructions.

The instructions say, as I understand it, that the broadcast will be available at: http://serialnumber.dvrhost.com:port
serialnumber and port are known. What is DVRHOST.COM is impossible to understand. Enumeration of dozens of combinations does not help. There is an error in the picture, a static ip is inserted instead of dvrhost.
have been tried:
provider site
DNS 1 and DNS 2
vendor site video recorder
model and serial number of the video recorder
static ip

Attempts were made to log in from various devices.

Device itself: Pinetron PDR-S2008

Answer 1

What is DVRHOST.COM I can't understand

DVRhost is a dynamic DNS service that redirects to your registrar.
Usually works at http://YOUR_HOST_NAME.dvrhost.com:7000
Where YOUR_HOST_NAME is the Host name for your registrar. It is usually displayed either in Network -> Dynamic or in System Info.
It looks like a set of seven characters, like G183F26.
The port may also not be 7000, but 7777.