Add a referral to your referral campaign with the following steps:
Go to the Purchases & Referrals Page.
Click Mark Purchase as Referred.
Click Confirm Referral to set the referrer.
Note: Once an advocate is set as a referrer, the advocate will be eligible for the current referral reward that is set for your campaign (view it on your Rewards page). When the referral reward will be sent to the advocate depends on the type of reward chosen, learn more here - When will rewards be sent to advocates?