Sends a broadcast message explicitly via REST API.
This method always uses the REST API endpoint regardless of WebSocket connection state. Useful when you want to guarantee REST delivery or when gradually migrating from implicit REST fallback.
Payloads that are ArrayBuffer or ArrayBufferView (e.g. Uint8Array) are sent as application/octet-stream; all other payloads are JSON-encoded.
The name of the broadcast event
Payload to be sent (required)
Options including timeout