Latest tailscale package from the unstable channel

I do love the concept of nixos and I am currently quite new to the OS, so I am learning by doing a lot. Since I am a heavy user of tailscale, I want to keep the package up to date, but somehow, I am not really sure how to do that on a stable release. This thread mentions how to reference a channel, so I did this like this:

{ config, pkgs, lib, ... }:
  unstable = import
    { config = config.nixpkgs.config; };
# Enable tailscale
  services.tailscale = {
    enable = true;
    port = 41641;
    package = unstable.tailscale;

Am I missing something? Some help would be appreciated!