Setting up prefixes to a URL with node.js

I am creating a Node.js server in the following standard format:

const https = require('https')

https.createServer(function(req, res){
    //Request handling code
}).listen(port, ip);

My question is how can I add prefixes to my url's such as: bugs.myurl.com or requests.myurl.com?

The standard req.url only provides you with the part of the URL

via Adam0410