How to find out your IP in VPN?

Question

VPN

What is the essence of the question: There is such a network diagram: https://1drv.ms/b/s!AjvFBb-z3q07iO9fxeVYgGs996_2Tg it is extremely simplified, but conveys the essence. I can't find out the IP address of the "URM" computer.
Initial: There is a server with an IP address of 19.2.168.10.1, on which the desired software is running. And there is a remote workplace (URP) that connects via VPN. The VPN server is a Mikrotik router. When a VPN connection is established, the network works correctly, that is, I can RDP into the server, get access to shared resources, etc.
Problem:It lies in the fact that I need to use software that is running on the server. It works on the principle of "server-client". On the server, I prescribe the allowed addresses of client machines and get access to this software from them. But I don't know the IP address of the URM machine and I can't set up software interaction. How can I find out the IP of the URM inside the LAN?
the arp -a command on the server, in addition to all connections known to me, gives the following at the end:

spoiler

224.0.0.22 01-00-5e-00-00-16 статический
224.0.0.251 01-00-5e-00-00-fb статический
224.0.0.252 01-00-5e-00-00-fc статический
239.255.255.250 01-00-5e-7f-ff-fa статический
255.255.255.255 ff-ff-ff-ff-ff-ff статический

There is no access to the Mikrotik web interface.

Answer 1

On Mikrot, go to IP - Addresses and see the address of the VPN account under which the URM connects.

More or less like this

Answer 2

If I understand correctly, there is no access to Mikrotik and nothing can be viewed on it. The remote machine is given an address from the 10th grid. Mikrotik is not natit. I can assume that you can look at the poppy address of the Mikrotik on the switch port and find out the ip of the remote machine from it in the arp table