How to use javascript libraries in javascript code?

When running in a browser, your source webpage should load the .js file containing the library, e.g.,:

<script type="text/javascript" src="http://your.cdn.com/somelib.js"></script>

In a stand-alone environment, like node.js, you use the require() statement:

const crypto = require('crypto');

To load the required libraries, you use the package manager npm:

npm install crypto

This will create a local copy of the library.