Directing internet traffic from devices behind Tailscale router through exit node

Sorry in advance if this is a dumb question since it must be such a common use case but I can’t find a recent article that puts together the various parts.
I have two network sites and what I want to do is direct the internet traffic from some devices on network 1 that can’t install the Tailscale software to use the exit node running on network 2.
I have the exit node on network 2 running and it happily allows devices directly enrolled on my Tailscale network to use it.
I can find articles about subnet routing allowing Tailscale devices access to other devices behind the subnet router but I am looking to go the other way and allow devices behind the router to access the Tailscale exit node. Is this supported on any of the available devices? I can lay my hands on an old mac mini and also a Pi if either could be set up to do this reliably?
Many thanks