how to get key param in URl by js code example

Example 1: javascript get url parameters

let url = 'https://www.example.com?name=n1&name=n2';
let params = (new URL(url)).searchParams;
params.get('name') // "n1"
params.getAll('name') // ["n1", "n2"]

Example 2: js get url parameter

const queryString = window.location.search;
const urlParams = new URLSearchParams(queryString);
const code = urlParams.get('code')