Create refund

curl --request POST \
  --url https://sandbox.kulmipay.com/api/v1/chargebacks \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "transaction": {
    "invoice": {
      "value": "<string>",
      "charges": "<string>",
      "account": "<string>",
      "api_ref": "<string>",
      "host": "<string>",
      "retry_count": -1,
      "failed_reason": "<string>",
      "failed_code": "<string>"
    },
    "narrative": "<string>"
  },
  "amount": "<string>",
  "resolution": "<string>"
}
'

{
  "transaction": {
    "invoice": {
      "value": "<string>",
      "invoice_id": "<string>",
      "charges": "<string>",
      "net_amount": "<string>",
      "currency": "<string>",
      "account": "<string>",
      "api_ref": "<string>",
      "clearing_status": "<string>",
      "mpesa_reference": "<string>",
      "host": "<string>",
      "retry_count": -1,
      "failed_reason": "<string>",
      "failed_code": "<string>",
      "failed_code_link": "<string>",
      "created_at": "2023-11-07T05:31:56Z",
      "updated_at": "2023-11-07T05:31:56Z"
    },
    "transaction_id": "<string>",
    "currency": "<string>",
    "value": "<string>",
    "running_balance": "<string>",
    "narrative": "<string>",
    "created_at": "2023-11-07T05:31:56Z",
    "updated_at": "2023-11-07T05:31:56Z"
  },
  "chargeback_id": "<string>",
  "session_id": "<string>",
  "amount": "<string>",
  "status": "<string>",
  "resolution": "<string>",
  "staff_created": true,
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z"
}