CreateRefundRequest

{
    "request_id": "string",
    "payment_id": "string",
    "payment_request_id": "string",
    "account_id": "string",
    "notify_url": "string",
    "refund": {
        "amount": 0,
        "reason": "string"
    },
    "metadata": {
        "property1": {},
        "property2": {}
    }
}