We are implementing promo/offer codes for our iOS app’s subscription in-app purchases and have several technical questions regarding validation, receipt data, and integration. Could you please provide guidance on the following points? Testing/Validating Custom Codes Without Production Release: How can we validate custom promo/offer codes in a non-production environment? Current documentation indicates promo codes only work in production, requiring app submission and future release date setup for testing. Receipt Data for Redeemed Codes: The receipt currently includes only offer_code_ref_name, not the exact redeemed code (e.g., “ABC123”) entered by the user. Is there a way to retrieve the specific offer code used via receipts, App Store Server API, or other endpoints? Server-Side Validation Best Practices: What are the recommended best practices for server-side validation of offer codes, including using App Store Server API for transaction verification? Passing appAccountToken for Coupons: How can we pass an appAccountToken when users redeem coupon/offer codes (e.g., via presentOfferCodeRedeemSheet or redemption flows)? StoreKit purchase options support it for regular purchases but not redemption sheets. Callbacks on Coupon Redemption: Is there a client-side callback or notification (e.g., via updatedTransactions or StoreKit observers) when a user successfully redeems a coupon code in the app? Server notifications are received, but app-side feedback appears unreliable.