nix-config/systems/common/core/xorg_plasma.nix

{ 
     services = {
         xserver = {
             # Enable the X11 windowing system
             enable = true;
     
             # Enable Keymap
             xkb = {
                 layout = "us";
                 # variant = "qwerty";
                 # model = "thinkpad";
             };
         };
         # KDE X
         displayManager.sddm.enable = true;
     }; 
}