Firefox does not use KDE window decorations and cursor

I installed NixOS choosing Plasma (KDE) and then activated Wayland and installed firefox-wayland. Firefox is not properly integrated into KDE:

  1. Windows decorations are from Gnome (GTK?) and not KDE
    image

  2. The mouse cursor does not scale and looks different over Firefox windows. I am using a 200% scaling and the cursor changes to the small, unscaled, size. The cursor becomes tiny and hard to see. It also does not use the KDE style

    Outside of Firefox window:
    image

    Inside Firefox window:
    image

I checked the Wiki pages for Firefox and KDE and applied the Wayland settings suggested in the Firefox page but it did not resolve my issues.

How can I make Firefox use KDE window decorations and the normal KDE cursor with scaling?

Enabling dconf worked for me.

programs.dconf.enable = true;