Hello. I'm currently implementing Apple Notification v2 to prepare for refunds for in-app purchases, but I'm not receiving requests from Apple servers to my backend server. I've applied HTTPS (TLS 1.2) and correctly registered production/sandbox notification URLs on App Store Connect. After requesting a test notification, when I check the status of testNotificationToken, I receive an UNSUCCESSFUL_HTTP_RESPONSE_CODE as follows: {"signedPayload":"......":[{"atteptDate":1752128001970,"sendAttemptResult":"UNSUCCESSFUL_HTTP_RESPONSE_CODE"}]} The endpoint for receiving notifications is set to accept POST requests with application/json format, and it responds with 200 (OK) without any content. However, Apple notifications are not coming through. Could anyone help me with this issue?

Hello. I'm currently implementing Apple Notification v2 to prepare for refunds for in-app purchases, but I'm not receiving requests from Apple servers to my backend server. I've applied HTTPS (TLS 1.2) and correctly registered production/sandbox notification URLs on App Store Connect. After requesting a test notification, when I check the status of testNotificationToken, I receive an UNSUCCESSFUL_HTTP_RESPONSE_CODE as follows: {"signedPayload":"......":[{"atteptDate":1752128001970,"sendAttemptResult":"UNSUCCESSFUL_HTTP_RESPONSE_CODE"}]} The endpoint for receiving notifications is set to accept POST requests with application/json format, and it responds with 200 (OK) without any content. However, Apple notifications are not coming through. Could anyone help me with this issue?