You need an invite code from the mesh owner: the command they send you ends in it.
Linux and macOS, in a terminal:
curl -sL mesh.lunarz.dev|shWindows, in an administrator PowerShell:
irm mesh.lunarz.dev|iex
It installs Cloudflare WARP if needed and enrols this machine: internet through WARP, your local networks untouched, and the mesh reachable. To leave:
curl -sL mesh.lunarz.dev/leave|shirm mesh.lunarz.dev/leave|iex