curl --request POST \
  --url https://api-eu.flexportal.io/v1/payments/{paymentId}/cancel \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'Tenant-ID: <tenant-id>' \
  --data '
{
  "reason": "<string>"
}
'

{
  "success": true,
  "message": "<string>",
  "payment": {
    "paymentId": "<string>",
    "tenantId": "<string>",
    "customerId": "<string>",
    "subtotal": 1,
    "total": 1,
    "currency": "<string>",
    "paymentType": "individual",
    "billingPeriod": "<string>",
    "status": "pending",
    "idempotencyKey": "<string>",
    "dueDate": "<string>",
    "createdAt": "<string>",
    "updatedAt": "<string>",
    "taxAmount": 0,
    "taxRate": 0,
    "amount": 1,
    "rentalId": "<string>",
    "billingGroupId": "<string>",
    "provider": "stripe",
    "transactionId": "<string>",
    "providerResponse": {},
    "manuallyMarked": false,
    "paymentReference": "<string>",
    "markedBy": "<string>",
    "captureAttempts": 0,
    "lastCaptureError": {
      "code": "<string>",
      "message": "<string>",
      "declineCode": "<string>"
    },
    "lineItems": [
      {
        "rentalId": "<string>",
        "description": "<string>",
        "amount": 1,
        "taxAmount": 0
      }
    ],
    "lateFeeApplied": false,
    "lateFeeAmount": 1,
    "originalAmount": 1,
    "notes": "<string>",
    "paidAt": "<string>",
    "lastCaptureAttempt": "<string>",
    "nextRetryAt": "<string>"
  }
}