Hi Alex,

Luke from the Product team here. Thanks for submitting this feature request!

Based on their API docs, Klaviyo doesn't provide that field on the Coupon Code endpoint: https://developers.klaviyo.com/en/reference/get_coupon_codes_for_coupon. 

We found this workaround in the Klaviyo community forum: https://community.klaviyo.com/marketing-30/coupon-assigned-date-in-api-14214. Here is the workaround:

 I ended up finding a workaround using the get events API endpoint and filtering based on the coupon assigned metric ID.

I expect you could get this data using our EVENT table. Could you try that approach and let me know if it works? Without this field available on the Coupon Code endpoint, I don't see another way we could support this use case. 

Cheers,
Luke