Setting up domain

Right now its url is [my-ip-address]:8000 but I need to make the url as I tried domain setup in frappe. But I could not make it work .
The command executed successfully.

But nothing happens when I open the url .

maindomain is already pointed the vps.

Also Can I install another instance or a fresh copy on the same vps. How could I change change its port if by default it installs uses 8000.

Check port based multi-tenancy