How to set up a VPN server in one?

Question

Debian

There are two servers on one is worth VPN WIREGUARD and the other server is connected to it.
The network behind the VPN server is visible, how to share the network behind another server? The router where another server is connected does not support a VPN connection, I do not want to change to another one.

How can I solve this issue, having two servers, and both have white ip?
I apologize for the stupid question, I didn’t have much to do with VPN, in such a situation.