OpenVPN Routes

I have installed OpenVPN server, the client gets a VPN address, it can ping the VPN server but not the local network that the server sits on. I think I need to add rules/routes to the server.

Client Range - 192.168.4.0/24

Server Local range -192.168.6.0/24

How would I add a route to the server so clients can access the local range?

Many thanks in advance