First make sure nodejs and npm are installed on your host machine. After installation, we go to the folder of the lab we want to practice. "i.e /skf-labs/XSS, /skf-labs/RFI/" and run the following commands:
$ npm install
$ npm start
Now that the app is running let's go hacking!
The application shows that there is a new version of the website available somewhere, and a click on the button "Go to new website" will redirect you to it.