Sonos HTTP API - run commands to Sonos via http

I am having a hard time getting this going. I did the npm install sonos and it seemed to do that and it put it into the node_modules directory. However in step 5 above, where am I supposed to run this command from? I am using windows so do I run it in the command screen? I have tried to do this but I am getting an error module.js:471 throw err. I think I am missing something.