curl --request POST \
  --url https://app.flowglad.com/api/v1/payments/{id}/refund \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '{
  "partialAmount": 123
}'

{
  "payment": {
    "id": "<string>",
    "createdAt": 0,
    "updatedAt": 0,
    "livemode": true,
    "invoiceId": "<string>",
    "amount": 4503599627370495,
    "paymentMethod": "card",
    "currency": "USD",
    "status": "canceled",
    "chargeDate": 0,
    "settlementDate": 0,
    "description": "<string>",
    "receiptNumber": "<string>",
    "receiptURL": "<string>",
    "organizationId": "<string>",
    "customerId": "<string>",
    "purchaseId": "<string>",
    "subscriptionId": "<string>",
    "paymentMethodId": "<string>",
    "billingPeriodId": "<string>",
    "taxAmount": -1,
    "subtotal": -1,
    "taxType": "amusement_tax",
    "taxCountry": "AD",
    "taxState": "<string>",
    "taxRatePercentage": "<string>",
    "applicationFee": -1,
    "refunded": true,
    "refundedAmount": -1,
    "refundedAt": 0,
    "failureMessage": "<string>",
    "failureCode": "<string>"
  }
}