...Both modes require you to be serving your web application from a local web server, which is started from either a VS Code task or from your command line. Using the URL parameter you simply tell VS Code which URL to either open or launch in Chrome. Just like when using the Node debugger, you configure these modes with a .vscode/launch.json file in the root directory of your project. You can create this file manually, or Code will create one for you if you try to run your project, and it doesn't exist yet.