LineItem

{
    "description": "string",
    "amount": 0,
    "amount_excluding_tax": 0,
    "currency": "string",
    "quantity": 0,
    "period": {
        "start": 0,
        "end": 0
    },
    "plan": {
        "amount": 0,
        "currency": "string",
        "interval": "string",
        "interval_count": 0
    }
}