send original transaction with correct format for Klarna MoR

Author: gentiprenaj

src/Gateways/Klarna/KlarnaFulfillmentActions.php

@@ -134,7 +134,10 @@ protected function dispatch_data_request(WC_Order $order, string $sdkMethod, str
         $response = $payment->method($gateway->getServiceCode($processor))->{$sdkMethod}(
             array_merge(
                 $processor->getBody(),
-                ['originalTransactionKey' => $dataRequestKey]
+                // Klarna's `klarna` service references the original reserve via
+                // a service-level `DataRequestKey` parameter (the SDK's `Pay`
+                // model exposes it as `dataRequestKey`).
+                ['dataRequestKey' => $dataRequestKey]
             )
         );
 

src/Gateways/Klarna/KlarnaPayGateway.php

@@ -110,7 +110,10 @@ public function cancel_reservation(WC_Order $order)
             $payment->method($this->getServiceCode($processor))->cancelReserve(
                 array_merge(
                     $processor->getBody(),
-                    ['originalTransactionKey' => $dataRequestKey]
+                    // Klarna's `klarna` service references the original reserve via
+                    // a service-level `DataRequestKey` parameter (the SDK's `Pay`
+                    // model exposes it as `dataRequestKey`).
+                    ['dataRequestKey' => $dataRequestKey]
                 )
             ),
             $order

src/Gateways/Klarna/KlarnaProcessor.php

@@ -26,7 +26,11 @@ protected function getMethodBody(): array
             $dataRequestKey = get_post_meta($this->get_order()->get_id(), self::DATA_REQUEST_META_KEY, true);
 
             if (is_string($dataRequestKey) && strlen($dataRequestKey) > 0) {
-                $body['originalTransactionKey'] = $dataRequestKey;
+                // Klarna's `klarna` service identifies a reservation by a service-level
+                // `DataRequestKey` parameter (not the top-level `OriginalTransactionKey`).
+                // Sending it as `originalTransactionKey` causes Buckaroo to reject the
+                // capture with "originaltransaction is invalid for the action Pay".
+                $body['dataRequestKey'] = $dataRequestKey;
             }
         }