You’re in the right way. The subnet of the router can’t be the same as WireGuard.

You have two routers. Using one of them as client, another as server, you can access server’s LAN from client’LAN by default.

But if you want to access client’s LAN from server’s LAN, you have to ssh to the router, add your client’s subnet to /etc/config/wireguard_server, it looks like:

image

Finally, you should restart WireGuard server in admin web page.

It should be simple to do.