(verifyreceipt) I cannot verify from the server whether the user's iap payment is successful or not

I have three questions about verify receipt

1. I use this api （https://buy.itunes.apple.com/verifyReceipt）to verify receipt is success or not. But since last month, this interface has started to return an error(21002).

I see this document (https://developer.apple.com/documentation/appstorereceipts/verifyreceipt) say its Deprecated. My question is, is the error suddenly returned recently because the interface has been deprecated or for some other reason? (I haven't modified my code about this recently) 2. I can not understand this document: （https://developer.apple.com/documentation/appstorereceipts/validating_receipts_on_the_device） Does this mean that in the new version, as long as the app returns a payment success (purchaseDetails.status == PurchaseStatus.purchased), the payment is guaranteed to be successful, and my server does not need to request payment result verification from Apple's server? 3. I try to use this (https://github.com/apple/app-store-server-library-java) to get TransactionInfo, but I dont konw to get Transaction status to know is success or not.

my java server code : AppStoreServerAPIClient client = new AppStoreServerAPIClient(encodedKey, keyId, issuerId, bundleId, environment); TransactionInfoResponse response = client.getTransactionInfo(transactionId); (bug i can note get transaction status, how do i konw this Transaction is success or not)