退款處理

執行付款授權後自動處理為請款，或執行分開請款則無法取消已授權的付款，只能採取退款處理。可以使用已完成付款的交易ID (transaction ID)退還全部付款金額，如下所示。

呼叫Online API時，取得必要credentials的方法請參考準備API credentials。本頁所述的程式碼範例使用準備API credentials程式碼範例中定義的requestOnlineAPI()函數。

try {
  let refundResponse = await requestOnlineAPI({
    method: "POST",
    baseUrl: targetAPIServer,
    apiPath: `/v3/payments/${transactionId}/refund`,
  });

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

處理交易ID訊息時，根據服務執行語言，可能需要將交易ID視為字串。詳細說明請參考交易ID (transaction ID)。

只需要退還部分金額，請在主體參數部分輸入要部分退款的金額(refundAmount)，如下所示。

const refund = async function (transactionId, amount = 0) {
  if (!transactionId) throw new Error("Transaction ID is required!");
  if (amount < 0) throw new Error("Amount cannot be negative number");

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

  let refundResponse = await requestOnlineAPI({
    method: "POST",
    baseUrl: targetAPIServer,
    apiPath: `/v3/payments/${transactionId}/refund`,
    data: refundBody,
  });

  return refundResponse;
};

// ...

try {
  let response = refund("2018082512345678910", 500);

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

如果退款處理要求正常進行，則會回傳以下退款交易訊息回應。

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