How to route all ipv4,ipv6 traffic to a specific IP

I am creating 2 wireguard servers. The setup is here

https://www.reddit.com/r/WireGuard/comments/q5wqyl/route_peers_to_another_peer/

This is probably the more appropriate place to post this.

My wireguard local subnet is 10.0.3.0/32

I need to setup IP routing that will route all traffic from source 10.0.3.0/32 directly to 10.0.3.2, and then all traffic from source fd00:0:3::/128 directly to fd00:0:3::2.

I have other wireguard interfaces so this needs to be source based routing so my other subnets can still access through their default routes.

I am completely lost on how to do this. Can someone show me an example of how to create a device specific ip route table for device rpi1 that routes all traffic from this device (10.0.3.0/32) to 10.0.3.2? Thanks!