This part always confuses me, so I won’t be able to give specifics; just a general direction. Most guides explain how to route traffic from a vpn client to the lan of the vpn host. You need to route traffic from the vpn host/lan to a client of the vpn.

You need to change the routing table on the VPS, add8ng a static route to route traffic for your VPNs subnet to the VPN network interface instead of the default gateway.

How exactly to do that I’ll have to leave to someone else unfortunately. Network config confuses the hell out of me.