To provide a little more detail (Joshua - please correct if I'm mistaken and you have a different type of code you are offering), the referral code is for use when purchasing a Pixel 6a, Pixel 7, or Pixel 7 Pro from the USA Google Store while logged into the store with your Google account.
Within 30 days after the phone ordered using the code is shipped, a coupon code is emailed which provides a $100 credit towards a future purchase of a device, valid through September 30, 2023 (unfortunately not long enough to apply towards a Pixel 8-series device unless orders open much earlier than the usual Pixel launch timeframe).
The code can currently be used in conjunction with other discounts such as the one provided by certain Google One subscriptions, and (at least so far) other promotions from Google (such as sale prices) and trade-in credits.
Should Joshua's code be on 'cooldown' (after a code is used, the code-give does not have another code available until after the device purchased with the previous code is shipped), I can also provide one - as can many others on the forums - so there should not be an instance in which we can help one another out; in short, there's no downside to taking advantage of this referral program.