Module has an unsupported attribute `services'. (services.gnome.chrome-gnome-shell.enable)

I added this in my configuration.nix and got this error.

## https://discourse.nixos.org/t/cannot-activate-the-gnome-extensions/15594/3
config.firefox.enableGnomeExtensions = true;
services.gnome.chrome-gnome-shell.enable = true;

line 1 seems not to bother it, but line 2 balks.

At top is:

{
config,
pkgs,

}: {

other stuff

above

}

I have no idea what it means.

Similar to Whats wrong? `/etc/nixos/configuration.nix' has an unsupported attribute `boot' , i guess