OPNsense in the cloud, lab at home

[gustaf]

I'd like to conduct a new experiment and setup OPNsense as a VPS machine.
The only purpose of this VPS would be to provide a VPN connection for my self hosted lab.
I don't know how to set things up since the VPS would only get one public IP and there would basically be no LAN side.

Here's the diagram:

Internet <> VPS OPNsense WAN (public IP) <> VPS OPNsense OpenVPN server interface (on the same public IP?) <> lab OPNsense OpenVPN client interface <> lab web server

I've tried to setup an OPNsense VM with one single NIC, and it was assigned to both LAN and WAN. I suppose this would not be optimal for security. OpenVPN works with this configuration.

I just want the VPS to forward all* requests to my web server, and the web server to access the web through the VPS public IP.

Thank you for your input

* "all" as in "all legitimate" and going through selected ports