Create TailScale tunnel between 2 pfsense

I need help with a project I have. I need to create a TailScale tunnel that connects 2 pfsense, the pfsense are already connected by an internal network and I need to create a tunnel that passes through that internal network and the tunnel must work without internet. Does anyone have a solution or know if it is possible to do it?

Technically I believe the connections between the tailscale nodes don’t require the internet once they found each other.
But in order to find each other (and get config changes for ACLs, DNS, etc.) they use the control server of Tailscale, which is on the internet.

But there is an open source variant of the control server that you could host on your own network, called “Headscale”.
I haven’t done that myself yet, but that way you should be able to keep everything off the internet.

Here’s a link to Headscale: GitHub - juanfont/headscale: An open source, self-hosted implementation of the Tailscale control server

Mind you though, Headscale doesn’t come with a web-gui, so if you want something like that, then here’s one: GitHub - gurucomputing/headscale-ui: A web frontend for the headscale Tailscale-compatible coordination server