Now unified receipt is an des ordered array so take the latest receipt only

src/model/NotificationPayload.php

@@ -86,7 +86,7 @@ class NotificationPayload
         }
         $instance->latestExpiredReceipt = $request->input('unified_receipt.latest_expired_receipt');
         if ($request->has('unified_receipt.latest_expired_receipt_info')) {
-            $instance->latestExpiredReceiptInfo = Receipt::createFromArray($request->input('unified_receipt.latest_expired_receipt_info'));
+            $instance->latestExpiredReceiptInfo = Receipt::createFromArray($request->input('unified_receipt.latest_expired_receipt_info')[0]);
         } else {
             $instance->latestExpiredReceiptInfo = null;
         }