"window not defined" when rendering CSR app on Server

[aptDroid]

I have declared "window" in my express app as:

const Window = require('window');
const window = new Window();
const express = require('express');

I logged window object in my react component uses window object as:

const MyComponent = () => {
window.abc = 2;   //gives error, window not defined
console.log(abc);

return(<h1>{window.abc}</h1>);
}

I get error "undefined" at the first line "window.abc = 2"