laravel-ratchet | laravel websocket using ratchet | Websocket library

I am new to websockets and I want to implement such service in my Laravel application. I have already read several posts/pages about this topic, but none explains what I need to do. All of them show how to create an "Echo" websocket server, where the server only responds to messages received from clients, which is not my case.

As a starting base I used the code provided at:

https://medium.com/@errohitdhiman/real-time-one-to-one-and-group-chat-with-php-laravel-ratchet-websocket-library-javascript-and-c64ba20621ed

Where the websocket server is ran from the command line or another console. The server has its own class to define it and imports the WebSocketController class (MessageComponentInterface), which contains the classic WebSocket server events (onOpen, onMessage, onClose, onError).

All that works fine as is but, how can I "tell" the WebSocket Server to send a message to a specific connection (client) from another class, which also belong to another namespace?. This is the case of a notification or event, where new web content must be sent to that specific client. There are no subscriptions nor publications on the way from the client side.

As @Alias asked in his post Ratchet PHP - Push messaging service I obviously cannot create a new instance of the Websocket server or its events management class, so what would be the best approach to send content or messages to the client?

As you all can see, the communication is only in one way: from the WebSocket Server to the client(s) and not the opposite. I already have a notification class and a listener class prepared for this but, I still don't know how to address the communication with clients from the handle() method: