Hi @c2323r234, 

Thanks for being a part of our community! Looking into this, it looks like it's the updated field - we assume the last updated timestamp to be when the coupon code was assigned. When it comes to locating this information - we do not expose the updated field on the API. With that said, if you create a custom report using the Coupon Assigned event instead, that should help to meet your goal. I have shared your feedback with the product team on this. I hope this helps!

~Chloe

Thanks for sharing the feedback with your product team. I ended up finding a workaround using the get events API endpoint and filtering based on the coupon assigned metric ID.