Can't find Lightdm Greeter ui file

So, I am only starting my NixOS journey, so please, be kind.
Anyway, to the question:
After I found how to browse through services, I set up my background, etc…
And when I tried to find service that allows to disable topbar panel… I couldn’t. Because this is need to be done in greeter.ui file… which I couldn’t find in /usr/share/lightdm-gtk-greeter/greeter.ui,

So, my question is, where those files are created when you enable lightdm through services.xserver.displayManager.lightdm.enable = true ?

The greeter.ui file doesn’t seem to be in use anymore.

1st check with the lightdm-gtk-greeter developers to see how to disable the topbar; If that’s even possible without modifying the code. If it can be done with a configuration, then it’s quite likely it can be done through a NixOS module.

Will try… But it’s a shame, really. Or not. Will post here what will be the end of it.

But, maybe, someone could answer where *.conf files on NixOS, for start…?

Most “.conf files” on NixOS are not stored at a fixed location. They are generated by NixOS modules, and stored somewhere in the Nix store. The various services are executed in such a way that they can find their configuration files.

The lightdm GTK greeter NixOS module doesn’t have anything specific for your use-case, see NixOS Search

But, it does have a .extraConfig option which allows users to inject raw configuration settings into the gtk greeter configuration file. I suggested that you ask the greeter’s devs, (or reference their docs), because if they have a config setting for what you’re looking for, then you may be able to use the .extraConfig option. Here’s how the configuation is injected, which is important:

Okay, so. While I couldn’t find options for gtk-greeter, I found mini greeter, which has example on how to set some things, and already did what I wanted.
Here dev has example in readme:
So, while I couldn’t find answer on my question… I found a way to bypass it entirely…