We are currently experiencing an issue where our server is not receiving Apple’s server notification (webhook) for in-app purchase confirmations. This notification is critical as it helps us confirm the purchase status and fulfill the corresponding services to the users. Despite the successful completion of purchases within the app, the lack of webhook notifications prevents us from tracking and processing these payments on our backend. In addition to resolving this issue, we are also concerned about the security aspect of receiving server notifications. Specifically, we want to ensure that any requests or notifications we receive are indeed coming from Apple, and not subject to potential man-in-the-middle (MIM) attacks. We are looking for information or best practices on how to validate that the request originates from a legitimate Apple source, ensuring the integrity of the communication and safeguarding our system from spoofed or malicious requests. Key questions: Server Notification Issue: Why might we not be receiving Apple's payment confirmation notifications, and what steps can we take to troubleshoot this issue? Request Validation: What security mechanisms or validation techniques can we implement to confirm that the server notifications are genuinely from Apple, ensuring no interference from MIM attacks? Does Apple provide any headers, tokens, or signatures in the server notification that we can use to verify the origin? Are there any known methods or configurations to ensure secure receipt of in-app purchase confirmations? We are looking for guidance and possible solutions to ensure a secure and reliable payment validation process for our in-app purchases. Any support in this regard would be highly appreciated.