In the top left corner, there is the name of the project, "PIE Nodejs", click on the name and you should see the button outlined in red:
The fork button
When you click on this button, the project will be copied into your user account. After "forking" the project, you can just click run as everything has been set up for you.
The run button.
Any changes made to index.js file will require a server restart but any .html file changes will apply straight away after you save.