I have a model a2854 but this I can't fin d it in my computerI

A2854 is the model number for the latest model Siri Remote — not for the Apple TV box.

Identify your Apple TV remote - Apple Support

Identify your Apple TV model - Apple Support

Find your Apple TV model number - Apple Support

I can't find it in my computer

What do you hope to find in your computer? What are you trying to do?

Apple TV 4K is not supposed to connect to a computer.

The Siri Remote is not supposed to work on computers.

only place an appletv box would show up in your computer is in itunes (widnows)/ apple music app as airplay speaker