handle refunds, when buy consumables product, how to test App Store Notifications callback url?

when SKPaymentTransactionStatePurchased get SKPaymentTransaction value ：transaction.payment.applicationUsername is null base: Xcode Version 12.0 beta (12A6159) iOS 14.0 (18A5301v) print： (lldb) p transaction.payment.applicationUsername (NSString *) $1 = nil Will the official version of iOS 14 always be like this? please~

(BOOL)paymentQueue:(SKPaymentQueue *)paymentQueue shouldContinueTransaction:(SKPaymentTransaction *)transaction inStorefront:(SKStorefront *)newStorefront; Asks the delegate if the transaction should continue if the device's App Store storefront has changed during a transaction. ref: Apple Developer Documentation - https://developer.apple.com/forums/content/attachment/9a62a7a9-d26a-4ba6-945e-bd58fd6ad7af but in Xcode document: @protocol SKPaymentQueueDelegate <NSObject> @optional // Sent when a user has initiated a purchase of a Promoted IAP from the App Store (BOOL)paymentQueue:(SKPaymentQueue *)paymentQueue shouldContinueTransaction:(SKPaymentTransaction *)transaction inStorefront:(SKStorefront *)newStorefront API_AVAILABLE(ios(13.0), macos(10.15), watchos(6.2)); Sent when a user has initiated a purchase of a Promoted IAP from the App Store Way ? Way ? Way ? only for a Promoted IAP ??? only for a Promoted IAP ??? only for a Promoted IAP ??? My Problem： So hopefully you can parse, does this API work in App？ or for a Promoted IAP from the App Store ?

@Frameworks Engineer   This delegate no calls in iOS13 : //  SKPaymentQueue.h @protocol SKPaymentQueueDelegate <NSObject> @optional // Sent when a user has initiated a purchase of a Promoted IAP from the App Store (BOOL)paymentQueue:(SKPaymentQueue *)paymentQueue shouldContinueTransaction:(SKPaymentTransaction *)transaction inStorefront:(SKStorefront *)newStorefront API_AVAILABLE(ios(13.0), macos(10.15), watchos(6.2)); Availability iOS 13.0+ This method paymentQueue:shouldContinueTransaction:inStorefront: Availability iOS 13.0+, In fact, is not work for iOS13 When I asked if there was a documentation error, the engineer replied that it was a documentation error: Respond to Storefront Changes no work for me | Apple Developer Forums - https://developer.apple.com/forums/thread/657128?answerId=627774022 So，the comment in this header file is a mistake ？ or  Developer Documentation website is a mistake ? paymentQueue:shouldContinueTransaction:inStorefront: this method is work under what conditions does it take effect ？