The referral reward coupon code has not yet been created on your eCommerce platform.

Check that you have created the referral reward coupon code in your eCommerce platform's admin panel.

For most platforms, you'll have to create the coupon codes yourself. If the coupon code doesn't exist, please create it.

The referral reward coupon code is no longer valid (e.g., it has been used or has expired).

Check the validity of the referral reward coupon code in your eCommerce store's admin panel.
​
If invalid, issue the Advocates with a new coupon code if you'd like them to be able to still claim their reward.

The referral reward coupon code purchase conditions are not met.

When creating the referral reward coupon code, you may have set some purchase conditions that have to be met before the coupon code is valid for use.
​
Check that the Advocate's purchase fulfills these conditions.