expressja make http request using xhr or fetch

I have a simple expressjs script like:

var app = require('express')();
var http = require('http').Server(app);

var requestAuth = function (req, res, next) {
  var xhr = new XMLHttpRequest()
  console.log("a", xhr)
  next()
}
app.use(requestAuth)

app.get('/', function(req, res){
  res.send('<h1>Hello again</h1>');
});

http.listen(3000, function(){
  console.log('listening on *:3000');
});

Here I want to make simple ajax call and check for authentication in url.

Whhen I execuste the above script it gives me error like XMLHttpRequest is not defined. What is the issue here ?

Same type of error I got when I tried using promise

How can I make http request using xhr or fetch ?

Isnt it nodejs should accept all the functions that normal javascript accept ?

Can anyone make me more clear ? I am very new to expressjs

via aryan