There is an opportunity to add a referral code when you first sign up and log into the application.
If a referral code was sent via text or with a link, the code must still be entered upon signing up. Clicking on the link will not automatically apply the referral code.
If you missed adding the referral code at sign up, you can still add it before you scan your first receipt. You can enter it by going to the Me tab at the bottom of the app and selecting Referral Code. On that page, you will be able to enter the code. You are unable to enter it after once you submit a receipt.