How to make server ports?

Question

Remote access

Help out guys.
There is a modem, there is a dedicated IP.
The modem is redirecting to the server port.
But it is necessary that users can not only connect via remote IP but also locally.
Because the computer and the server are on the same network. The server does not have a dynamic IP, but a static one.
In short, what is needed is for users to connect to the server locally.
On the screen, I did port forwarding like this:

Answer 1

but also locally

Let them connect to the local address.

Connected with a separate cable to the router.

Make a route from the local network to the server.

Answer 2

It does not bother that RDP works on port 3389, and you have 3388 resolve.