How to Remove Port Number From URL of Node JS Application?

I am new to node js. In my application url, the port number must be specified like localhost:3000/a.
How to remove the port number from the URL. I tried setting the port number to 80. But it's useless to me.
Even if I set the port to 8080, I must specify the port number 8080 to work. If not specified, a 404 will be raised, just like the behavior of a simple server.

If you want to use port 80, you should run the application with root/admin rights and make sure that no other server is running on this port. In fact, most people will deploy a reverse proxy to handle static content and route the remaining requests to the node.js application. nginx is usually used for this. You will find plenty of resources to explain how to do this.

Node js application calls the same function multiple times-stack overflow

Okay, so I have developed an application that can run 24/7. If I write this, I only have one question:

 setInterval(getWCProducts  , 1000*intervall); 

    function getWCProducts(){
      //code
    }

    function test(){
        console.log("Hello!")
    }
    test() 

It will call the test again and again. It will display "Hello!" almost every second. Why is the application like this? Obviously, the "real" function is not just about printing "hello!" The real function is the "setting function", which can prepare the application before it starts to cycle, and I can't let it run the setting function again and again.

The cycle only starts after completing the settings.

function main() {
     console.log("doing my main thing");
}

function setup() {
    console.log("doing my setup stuff ");
    setInterval(main, 1000);
}

What I want to point out is that for most real-world setInterval applications, you don’t want to start an interval call function separately, but really want to start an interval call each function after the last call. If this is the case, the modified code will look like this:

function main() {
     console.log("doing my main thing");
     setTimeout(main, 1000);
}

function setup() {
    console.log("doing my setup stuff ");
    main();
}