Hello Rob,
Unfortunately we do not have Tailscale on RUT200 as Tailscale package is very large in comparison to the device flash memory and RUT200 does not have enough flash memory space. Thank you for noticing that there is information about Tailscale on RUT200, I have contacted our department to remove this misleading section.
Tailscale is available on devices which has more free space, like RUTX series or other routers which have memory expansion with USB option, like RUT956. About USB tools you can read here more: RUT956 USB Tools - Teltonika Networks Wiki
As an alternative I would offer using WireGuard (requires atleast 1 public ip) which RUT200 has, Tailscale uses WireGuard connection protocol. For more information on how to set up WireGuard you can check out this guide: RUT200 VPN - Teltonika Networks Wiki
If you do not have public IP and want a VPN, then another alternative could be using RMS VPN or ZeroTier VPN.
Let me know if you have any further questions,
DziugasS