How client subscribe update in storage engine?

I try am bulding an inventory system using the storage engine. {I follow this tutorial}

Can the client subscribe updates from the server storage engine (no need poll the serv?
E.g. Player B send a gift item to Player A. How can player A client auto receive a new item update event from the server?

Is there any storage function like this one?

// Subscribe to the Status event.
socket.ReceivedStatusPresence += e =>

You cannot subscribe to changes on the storage engine, but you can use the notification system to achieve this behaviour, see: Heroic Labs Documentation.