create-a-retainerinvoice-request

{
    "customer_id": "460000000044001",
    "reference_number": " ",
    "date": "2013-10-01",
    "contact_persons_associated": [
        {
            "contact_person_id": 0,
            "communication_preference": {
                "is_email_enabled": true,
                "is_whatsapp_enabled": true
            }
        }
    ],
    "custom_fields": [
        {
            "customfield_id": "46000000012845",
            "value": "Normal"
        }
    ],
    "notes": " ",
    "terms": "Terms and conditions apply.",
    "location_id": "460000000038080",
    "line_items": [
        {
            "description": "The New York State Department of  Taxation and Finance",
            "item_order": 1,
            "rate": 1.23
        }
    ],
    "payment_options": {
        "payment_gateways": [
            {
                "configured": true,
                "additional_field1": "standard",
                "gateway_name": "paypal"
            }
        ]
    },
    "template_id": 0,
    "place_of_supply": "DU"
}