How to set up a bridge in SoftEther VPN?

Question

VPN

There is a central office. SoftEther VPN Server is deployed on the server in it.

And there is a remote office that has a gray external IP and no access to the router (no one knows the passwords, no one can reset them, they don’t know what and where at all)

The task is this. Install SoftEther VPN Bridge on their file server so that we can connect to remote network devices through it from the central office (some kind of legal backdoor)

The scheme is as follows:

Central office employee's computer -> Central office router (route to remote office network with SoftEther VPN Server adapter gateway) -> Central office server where SoftEther VPN Server is installed -> VPN bridge -> Remote office server with SoftEther VPN Bridge installed (it turns out that it must mask incoming traffic on its own behalf) -> Remote office employee's computer

The problem is that when I installed the bridge on a remote server and connected it to the central server, I got stuck, because I did not find normal manuals. Like looking at the IP address table on the central server - I see in the list of IP devices of the remote network. But on which gateway to prescribe the route to the remote network - it's not clear, the server's IP is not suitable, where to configure what - it's not clear.

Maybe someone has come across something similar? In principle, I don’t even mind if it is implemented in other software.