DirectCallInput

{
    "assistant_id": "b3a0271c-5834-40ff-bc5d-41ab5e39dfef",
    "contact_id": "f245e2a3-e141-4d41-912c-b1c1f5bd5598",
    "contact_phone_number": "string",
    "variables": {
        "property1": "string",
        "property2": "string"
    }
}