Process refund

If the payment was automatically captured or processed as a capture-separated payment after the payment request, you cannot void the confirmed payment and can only process a refund. You can process a full refund by using the order ID entered in the payment request as follows.

try {
  let refundResponse = await requestOfflineAPI({
    method: "POST",
    baseUrl: targetAPIServer,
    apiPath: `/v2/payments/orders/${orderId}/refund`,
  });

  console.log("Refund response: ", refundResponse);
} catch (error) {
  console.log(error);
}

If you want to refund only a partial amount, enter the amount to be partially refunded (refundAmount) in the body parameter as follows.

const refund = async function (orderId, amount = 0) {
  if (amount < 0) throw new Error("Amount cannot be negative number");

  const refundBody = amount > 0 ? { refundAmount: amount } : null;

  let refundResponse = await requestOfflineAPI({
    method: "POST",
    baseUrl: targetAPIServer,
    apiPath: `/v2/payments/orders/${orderId}/refund`,
    data: refundBody,
  });

  return refundResponse;
};

// ...

try {
  let response = refund("test_order_1", 500);

  console.log(response);
} catch (error) {
  console.log(error);
}

Once the refund request is successfully processed, the following refund transaction information is returned in the response.

{
  "returnCode": "0000",
  "returnMessage": "success",
  "info": {
    "refundTransactionId": 2018082512345678911,
    "refundTransactionDate": "2018-08-25T09:15:01Z"
  }
}