Message Received Webhook

{
  "event": "message.received",
  "instance_id": "demo_instance",
  "from": "15551234567@s.whatsapp.net",
  "chat_id": "15551234567@s.whatsapp.net",
  "message_type": "unknown",
  "message": null,
  "message_id": "MSG_DEMO_001",
  "timestamp": 1782582344,
  "media_url": "https://example.com/media/sample.jpg",
  "mime_type": null,
  "file_name": null,
  "has_media": false
}