Morning Brew Referral Program: Need Help Finding Details?

Hey yall! I have a referral program question! I cannot find it on the Beehiiv site anymore but what program is it that morning brew uses at the end? The one that gives product for referrals? There used to be a page that shared how to set this up with that specific company but I could not find it?? Does anyone remember the name of the company that works with Beehiiv and know the link on how to set that up?