curl --request POST \
  --url https://api.izap.ai/api/v1/transmissions/preview \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'business-id: <business-id>' \
  --data '
{
  "name": "<string>",
  "template_name": "<string>",
  "template_language": "<string>",
  "recipients": [
    {}
  ],
  "phone_column": "<string>",
  "transmission_type": "whatsapp_template",
  "max_messages_per_minute": 60,
  "variable_columns": {},
  "scheduled_at": "2023-11-07T05:31:56Z",
  "timezone": "<string>"
}
'

{
  "transmission_id": "tr1a2b3c-1234-4a5b-9c8d-abcdef123456",
  "name": "July promo",
  "status": "draft",
  "transmission_type": "whatsapp_template",
  "template_name": "order_confirmation",
  "template_language": "pt_BR",
  "recipient_count": 100,
  "valid_count": 98,
  "invalid_count": 2,
  "duplicate_count": 0,
  "estimated_duration_seconds": 60
}