Sometimes an affiliate will report that a discount code assigned to them is not working. Troubleshooting this issue is simple.
First of all, make sure that they are using the correct discount code specifically assigned to them.
Next, make sure that the discount code has been input and activated within Shopify.
If these two items have been verified and the discount code is still not working, please contact Enlistly Support so that we can help you troubleshoot further.