Restart VS Code and open the folder containing the project you want to work on.
Using the debugger
When your launch config is set up, you can debug your project. Pick a launch config from the dropdown on the Debug pane in Code. Press the play button or F5 to start.
The extension operates in two modes - it can launch an instance of Chrome navigated to your app, or it can attach to a running instance of Chrome. Both modes requires you to be serving your web application from 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.