proxy server node js - change ip request

proxy.js

import express from "express";
import httpProxy from "http-proxy";

const proxy = httpProxy.createProxyServer({
  changeOrigin: true,
});
const app = express();

function buildAuthHeader(user, pass) {
  return "Basic " + Buffer.from(user + ":" + pass).toString("base64");
}

app.use("", (req, res, next) => {
  // console.log('req '+req.headers['proxy-authorization']);
  // console.log(buildAuthHeader('admin', 'admin'))
  let userpass = buildAuthHeader('admin', 'admin');
  if (req.headers["proxy-authorization"] == userpass) {
    next();
  } else {
    res.sendStatus(403);
  }
});

app.get("*", function (req, res) {
  console.log("Request", req.method, req.url);
  proxy.web(req, res, { target: `${req.protocol}://${req.hostname}` });
});

app.listen(8500, function () {
  console.log("Listening on port 8500");
});