how to subscribe to a specific topic in node js using MQTT asynchronously

Question

I configured HiveMQ server and installed the MQTT npm package in the node js. I published the message to the HiveMQ server from different system in the same network.I want to subscribe the message asynchronously. How to achieve this? Code Snippet :

Published from different system to the HiveMQ

    client.on('connect', function(){
        client.publish('Test', 'test Message');
    });

Want to subscribe from HiveMq asynchronously

    client.on('connect', function(){
        client.subscribe('Test');
    });  

    client.on('message', function(topic, message){
    });