how to use a javascript file from another website code example

Example 1: javascript redirect

window.location.href = "http://mywebsite.com/home.html";

Example 2: javascript using another js file

// module.js
export function hello() {
  return "Hello";
}

// main.js
import {hello} from 'module'; // or './module'
let val = hello(); // val is "Hello";