In any case, updating the library version has resolved the problem. Thank you for your assistance!

Thank you for your response. Updating the Java App Store Server Library from version 2.1.0 to 2.2.0 resolved the issue. After the update, the notificationType, which was previously received as null, is now correctly received as ONE_TIME_CHARGE. However, it's worth noting that version 2.2.0 was only updated in the Maven Repository on June 16, 2024. During the time I was experiencing the issue, I was using the latest available version of the library, so I did not realize it was a version issue.

Where can I find the official documentation regarding your answer? It would be helpful if you could provide the link. Thank you! @App Store Commerce Engineer

@App Store Commerce Engineer Hello, I have checked the Feedback Assistant page, but I cannot find any response in the ticket(FB 13814988). Could you please verify where I can view the detailed response mentioned? Additionally, is there a page where I can view the list of App Store Server Notifications V2 that were sent to our server? Thank you for your assistance.

@App Store Commerce Engineer FB number: FB13814988 App Name: Reppley_DEV Bundle ID: com.reppley.reppleyDEV SKU: com.reppley.reppleyDEV TestFlight(Sandbox) account email: jwkim+3957@reppley.com, jwkim+0000@reppley.com Attached is a screenshot of the database storing App Store Server Notifications V2 alerts for the purchase of a subscription product:https://ibb.co/WkcKg4j