Restrict outgoing traffic to access only a specific set of IPs

I’m using the VPN server to accept requests from multiple clients, clients using this VPN can access a specific IP only, ie: any client using this VPN cannot send packets to any IPs except those that I configured.
I’m not sure if I can implement this within the VPN configuration? and how would I go about it?

Remove the route to disable routing all internet traffic than add the subnets or IP addresses that are allowed. There is no per-user configuration, this can only be applied at the server level and applied to the group of users attached to that server.