time is required; provide exactly one of customerId /customerExternalId to identify the customer on the appointment.{
"time": "2026-07-02T13:00:00.000Z",
"customerId": "9f2c8b7a4e1d6c3f0a5b8e2d7c4f1a9b",
"customerExternalId": "crm-7741"
}