You will receive an email containing a Wisdom Panel redemption code when you have hit the 120-day goal, as long as you've hit the goal within your first 180 days participating in the project.
If you haven't received an email yet, and you are eligible for the reward, head over to your Participant Portal here to find your reward.
Wondering how many Whistle Days you've logged? Check the Portal. You can also see your progress in the Whistle App. Simply tap the PAW icon in your Whistle app and follow along with the GIF below: