How do I get my Azure websites to run "node server.js"

How do I get my Azure websites to run "node server.js"

I'm new to Azure and NodeJS so I apologise in advance if this question is
confusing. I'm still trying to understand the basics. Right now, I have a
node.JS website that I'm just trying to deploy onto Azure as a webiste.
I have the website deployed using WebMatrix, however, I have a expressJS
server side where requires me to actually execute the code "node
server.js". On my local machine, I just execute this in command prompt and
my server boots up.
However, I'm not sure where I'm supposed to run this on azure?
Is it possible to do this using Azure's website service or do I need to
create another azure service type like maybe a cloud service or VM?