curl --request POST \
  --url https://api.revolv3.com/api/Invoices/{invoiceId}/refund \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json-patch+json' \
  --data '{
  "amount": 5
}'

{
  "invoice": {
    "invoiceId": 2,
    "parentInvoiceId": 1,
    "customerId": 1,
    "merchantInvoiceRefId": "202081d2-079d-478d-818e-28b428f843e0",
    "paymentMethod": {
      "paymentMethodId": 1,
      "billingAddressId": 1,
      "billingFirstName": "John",
      "billingLastName": "Doe",
      "merchantPaymentMethodRefId": null,
      "billingAddress": {
        "addressId": 1,
        "addressLine1": "1 Default Street",
        "addressLine2": null,
        "city": "Los Angeles",
        "state": "CA",
        "postalCode": "90210",
        "phoneNumber": null,
        "email": null,
        "country": "US"
      },
      "paymentMethodAchDetails": null,
      "paymentMethodCreditCardDetails": null
    },
    "invoiceStatus": "PartialRefund",
    "subtotal": 10.99,
    "tax": 0.1,
    "total": 11.09,
    "billingDate": "30-Oct-25",
    "merchantLegalName": "John Doe",
    "merchantCustomerRefId": "35fad91d-64c1-4a14-b0b7-ac59fff8e1c1",
    "customerFirstName": "John",
    "customerLastName": "Doe",
    "subscriptionId": null,
    "installmentId": null,
    "eligibilityFailReason": null,
    "merchantSubscriptionRefId": null,
    "networkTransactionId": null,
    "currency": null,
    "invoiceLineItems": null,
    "invoiceAttempts": null
  },
  "refunds": [
    {
      "invoiceAttemptId": 1,
      "amount": -3.99,
      "invoiceAttemptStatus": "Success",
      "invoiceAttemptDate": "2025-10-31T13:48:15.1479498Z",
      "paymentProcessor": "BridgePay",
      "processorTransactionId": null,
      "responseCode": null,
      "responseMessage": null,
      "processorRawResponse": null,
      "paymentMethod": {
        "paymentMethodId": 0,
        "billingAddressId": 0,
        "billingAddress": null,
        "billingFirstName": null,
        "billingLastName": null,
        "merchantPaymentMethodRefId": null,
        "paymentMethodAchDetails": null,
        "paymentMethodCreditCardDetails": null
      },
      "descriptor": {
        "subMerchantId": null,
        "subMerchantName": null,
        "subMerchantPhone": null,
        "countryCode": null,
        "city": null
      },
      "eligibilityCheckOrderCode": null,
      "processorMerchantId": null,
      "processingMethod": "None"
    }
  ],
  "refundedSubtotal": 5.99,
  "refundedTax": 0.05,
  "refundedTotal": 6.04
}