You bought a pack of 2 drivers, so you received:
- A fully equipped PCB, GRBL software already loaded and board tested on my K40
You will need to install and configure lightburn: Link to article
Then follow the assembly instructions to the letter in the article (installation part in the K40): Link to article
Take the time to follow each of these steps to make sure you don’t damage your machine or the shield!
Thank you again!