You only need to connect the 2 wires from the power button you install in your desk to the power 2pins for the front I/O on your motherboard and it's done. You will not be able to turn your PC from the power button on ur case but u will never need to use it again since u have one installed in ur desk. And if u need to remotely turn it on/off from ur mobile look on the internet for an mcu esp86 module Wich have a wireless chip and use the blynk app to control from ur phone . u may need to make a small pcb . Check this link "https://techreport.com/review/31438/building-a-pc-remote-starter-from-scratch/"
I already built this pcb and it's working very good.