Hi @liyam, thanks for reaching out. You will be pleased to know we have created an extensive getting started tutorial for the Pico Neo 2 Eye which you can follow @ https://vr.tobii.com/sdk/develop/unity/getting-started/pico-neo-2-eye/
This should get you up and running with our XR SDK development get. Please go through our documentation and let us know how you get on. Best wishes.