We are currently upgrading our server to IPv6, and when we tested it, we found that the following API, which verifies receipts when charging, resulted in an error. verifyReceipt API https://buy.itunes.apple.com/verifyReceipt https://sandbox.itunes.apple.com/verifyReceipt This is currently a deprecated API, so when we tried curling the URL to the "App Store Server API" and using nslookup, we also got an error. App Store Server API https://api.storekit.itunes.apple.com https://api.storekit-sandbox.itunes.apple.com The error was that the address could be retrieved from the domain in IPv4, but the address could not be retrieved in IPv6. "https://www.apple.com" and other sites could be retrieved without any problems in IPv6. Is this API not compatible with IPv6? If this is not possible, the only way to verify receipts and the legitimacy of charges seems to be to perform verification on the device, but as this requires a lot of work, I would like to know if there is a better way.