Using custom models (fox tails) in Fretta?

I’ve seen on some Fretta servers admins having their own custom tails, and I was told it’s based on this:

Now, I have no experience with bonemerging or anything like this, so does anyone know how I could use this model myself and restrict other players from using it? I’m using ULX on my server by the way.

:l

I have no experience in Fretta, but they’re probably using something like PAC to do that.