purchase

{
    "name": "string",
    "properties": {
        "eventType": "string",
        "currency": "string",
        "value": 0,
        "uniqueTransactionId": "string",
        "cart": [
            {
                "productId": "string",
                "quantity": 0,
                "itemPrice": 0,
                "size": "string"
            }
        ],
        "event_time": "string"
    }
}