If you want to install JavaScript in VSCode, install Visual Studio Code & Node.JS, create and run a JavaScript program, and then take these steps.

Do you need to perform an Ajax file upload with pure JavaScript? This example lays out the steps to accomplish an Ajax file upload without the need for a JavaScript library like jQuery or Dojo.

If you see JavaScript required to sign in error when using OneDrive, Skype, Teams or Office 365 apps, enable JavaScript in Chrome, Firefox, Edge.

Node.js is a lean, fast, cross-platform JavaScript runtime environment that is useful for both servers and desktop applications.

To enable JavaScript, go into the Settings app on your iPhone, click "Safari," then "Advanced," and swipe the JavaScript button to the right so it appears green. Here's a full breakdown with pictures.