The Nucleus Plus (and the Nucleus) do not support the use of Tailscale directly at this time because they use the BIOS boot mechanism which restricts the version of RoonOS to build 259 or prior. Build 271 is required to run Tailscale on the Nucleus. This build requires UEFI boot which is the mechanism employed by the Nucleus One and the Nucleus Titan.
Instead, you would have to install Tailscale on a separate computer (Raspberry Pi or equivalent is adequate) and configure it as a subnet router. See: