Problems w/ gtk.cursorTheme

I am trying to set a GTK cursor theme in home.nix:

gtk = {
  enable = true;
  cursorTheme = {
    package = pkgs.vanilla-dmz;
    name = "Vanilla-DMZ";
  theme = {
    name = "Dracula";
    package = pkgs.dracula-theme;

but I am getting the following error:

error: The option `gtk.cursorTheme' does not exist. Definition values:
- In `/home/user/.config/nixpkgs/home.nix':
      name = "Vanilla-DMZ";
      package = <derivation /nix/store/mi1lp9yfni8hj0dfyd7mhg2qi57mhl2n-vanilla-dmz-0.4.5.drv>;

Any ideas?

That is a rather recent option, introduced just six days ago: gtk: add cursor theme configuration (#2481) · nix-community/home-manager@e01facc · GitHub

Try updating the home-manager channel/flake input.

I tried updating the home-manager channel but still got the same error.