Help with WireGuard please

I assume your goal is to connect your two private networks, each of them behind another edge router?

It gets a bit tricky then. Not because any part of this in itself would be horribly complicated, but because you got a slightly more elaborate setup on your hands, and the whole will not work if you got any part of it wrong.

  • set up Wireguard on both of your OpenWrt devices
  • on each OpenWrt devices, enter the respective other peer's data (public key and IP range)
  • on the edge router in front of the OpenWrt device that acts as "server" have Wireguard's listening port forwarded to the OpenWrt device
  • if the "server" changes IP addresses, you need to take care of that on the "client" because Wireguard does not realize this on its own and will only resolve the "server" address once. Recently, a helper script became available for that, it comes with the wireguard-tools package.
  • if you want to reach the "outer" network around your OpenWrt devices through Wireguard, it becomes even more complicated

Not really "engineers", but this is definitely a topic for advanced users with at least a cursory knowledge about networking. With OpenWrt, most of the topics beyond basic operation are. Especially with anything beyond a basic setup, Wireguard definitely is not something that can be configured with just a few clicks (yet).