Not Working: Starting service from udev

service.nix

{
  systemd.user.services."setup-keyboard" = {
    enable = true;
    description = "Load my keyboard modifications";
    wantedBy = [ "multi-user.target" ];
    serviceConfig = {
      Type = "forking";
      ExecStart = "${pkgs.bash}/bin/bash ${pkgs.writeScript "setup-keyboard.sh" ''

        #!${pkgs.stdenv.shell}

sleep 1;

        # Stop previous xcape processes, otherwise xcape is launched multiple times
        # And buttons get implemented multiple times
        ${pkgs.killall}/bin/killall xcape

        # Load keyboard layout
        ${pkgs.xorg.xkbcomp}/bin/xkbcomp /etc/X11/keymap.xkb $DISPLAY

        # Capslock to control
        ${pkgs.xcape}/bin/xcape -e 'Control_L=Escape'

        # Make space Control L whenn pressed.
        spare_modifier="Hyper_L"
        ${pkgs.xorg.xmodmap}/bin/xmodmap -e "keycode 65 = $spare_modifier"
        ${pkgs.xorg.xmodmap}/bin/xmodmap -e "remove mod4 = $spare_modifier"
        ${pkgs.xorg.xmodmap}/bin/xmodmap -e "add Control = $spare_modifier"

        # Map space to an unused keycode (to keep it around for xcape to
        # use).
        ${pkgs.xorg.xmodmap}/bin/xmodmap -e "keycode any = space"

        # Finally use xcape to cause the space bar to generate a space when tapped.
        ${pkgs.xcape}/bin/xcape -e "$spare_modifier=space"

        echo "Keyboard setup done!"
      ''}";
    };
  };

  # SUBSYSTEM=="usb", ACTION=="add", RUN+="${pkgs.systemd}/bin/systemctl --user restart setup-keyboard"
  services.udev.extraRules = ''
        SUBSYSTEM=="usb", ACTION=="add", \
        ENV{ID_VENDOR}=="Ultimate_Gadget_Laboratories",\
        TAG+="systemd",\
        ENV{SYSTEMD_WANTS}="setup-keyboard.service"
  '';
}