firebase-admin node js use in browser

i trying to integrate firebase-admin for user mangement at web browser with node js but getting always a error as mention in blow image. enter image description here

I am create a bundle file and add this line var admin = require("firebase-admin"); and also make a file test.js and include this file into to html file.

Run this commad from terminal browserify bundle.js -o test.js

via Ig Muni