curl --request POST \
  --url https://stageapi.paymatrixpay.com/api/v1/merchant/payment/{mchOriginalTransactionId}/refund \
  --header 'Content-Type: application/json' \
  --header 'X-Merchant-Id: <x-merchant-id>' \
  --header 'X-Nonce: <x-nonce>' \
  --header 'X-Signature: <x-signature>' \
  --header 'X-Timestamp: <x-timestamp>' \
  --data '
{
  "merchant_transaction_id": "<string>",
  "merchant_refund_time": "<string>",
  "refund_currency_code": "USD",
  "refund_amount": 123,
  "reason": "商品质量问题",
  "remark": "客户退货退款"
}
'

{
  "code": "<string>",
  "msg": "<string>",
  "trace_id": "<string>",
  "data": {
    "platform_transaction_id": "<string>",
    "merchant_transaction_id": "<string>",
    "original_transaction_id": "<string>",
    "refund_data": {
      "refund_currency_code": "<string>",
      "refund_amount": 123,
      "actual_refund_currency_code": "<string>",
      "actual_refund_amount": 123,
      "refund_status": "<string>",
      "refund_time": "2023-11-07T05:31:56Z"
    }
  }
}