I donwloaded the mod, and I placed an advanced computer and a monitor on top and a keyboard in front of it. the keyboard just isnt activating the monitor or controlling it...

You have to connect your keyboard with wired modem and network cables.
And you have to run a small program for the keyboard and monitor to work.
It's in the example code repo:
https://github.com/tom5454/Toms-Peripherals/blob/api/examples/inWorldMonitor.lua