Start receiving a fax on the call. Returns a
FaxAction that resolves when the
fax is fully received or an error occurs.
This method emits calling.call.fax events. See Call Events for payload details.
Custom control ID. Auto-generated if not provided.
Callback invoked when the fax reception completes. The event contains the received document URL and page count.
Promise<FaxAction> — An action handle with
stop() and wait() methods.