In Testflight app on iphone, on entering promo code for in-app purchase, we are getting a success message from the app store on redeeming but the purchase success event in the react native code that works for in-app purchases is not being triggered. I found some discussions from a few years back that mentioned that promo codes only work in production environment. So do promo codes still only work in production environment or is there a way to test promo codes in testflight?

Our recent update was rejected saying the following Your app unlocks or enables additional functionality with mechanisms other than the App Store, which is not appropriate under App Store Review Guideline 3.1.1. Specifically, your app uses voucher code to unlock or enable purchase. It would be appropriate to remove these features from your app and any other feature that unlocks or enables functionality with mechanisms other than the App Store. You may also consider making this unlocked content available to your users as in-app purchases." The content was available as both an in-app purchase and using our custom promo codes which was a code set by us to make the product free. The promo codes provided by apple are unique while the offer codes seem to be only for subscriptions. Is there any way to use custom offer codes for one time in-app purchases?