Hi AdrianeSuhayda,
I'm Rodrigo and I will help you.
The page explains the details of how the feature works. To copy/and paste between devices, first, your device needs to be compatible (Surface Duo and selected Samsung devices).
After painting the device on Phone Link you need to activate the option on Settings > Features > Cross-device copy and paste.
When you copy something on the phone it will appear on the PC clipboard, and when you copy something on the PC it will appear on the phone clipboard.