Firebase Functions + express server infinite loop

[dudhatdhavalm]

when I run express in local it is working fine but when I use firebase function it does not load the page it went into an infinite loading.

const path = require("path");
const functions = require("firebase-functions");
const express = require("express");
const next = require("next");

// const port = parseInt(process.env.PORT, 10) || 3000;
// const dev = process.env.NODE_ENV !== "production";
const dev = false;
const app = next({
  dev,
  conf: { distDir: `${path.relative(process.cwd(), __dirname)}/next` }
});
const handle = app.getRequestHandler();

const server = express();
server.use(express.json());

server.get("/", (req, res, next) => {
  res.send("Hello");
});

server.get("/berlin/:type", (req, res) => {
  return app.render(req, res, "/", req.query);
});

server.get("/berlin/:type/:area/", (req, res) => {
  return app.render(req, res, "/", req.query);
});

server.get("*", (req, res) => {
  return handle(req, res);
});

nextApp = functions.https.onRequest(async (req, res) => {
  await app.prepare();
  return server(req, res);
});

module.exports.nextApp = nextApp;

next js config

const withCSS = require("@zeit/next-css");
const withPlugins = require("next-compose-plugins");
const isProd = process.env.NODE_ENV === "production";

function nextConfig(isProd) {
    let nextJsConfig;
    if(isProd) {
        nextJsConfig = {
            distDir: "../../dist/functions/next"
        };
    }
    else {
        nextJsConfig = {
            
        };
    }
    return nextJsConfig
}

module.exports = withPlugins([withCSS], nextConfig(isProd));

package.json script only

"scripts": {
    "dev": "next \"src/app\"",
    "build-app": "next build \"src/app/\"",
    "preserve": "npm run build-public && npm run build-funcs && npm run build-app && npm run copy-deps && npm run install-deps",
    "serve": "cross-env NODE_ENV=production firebase serve",
    "build-funcs": "babel \"src/functions\" --out-dir \"dist/functions\"",
    "build-public": "cpx \"src/public/**/*.*\" \"dist/public\" -C",
    "predeploy": "npm run build-public && npm run build-funcs && npm run build-app && npm run copy-deps",
    "deploy": "firebase deploy",
    "clean": "rimraf \"dist/functions/**\" && rimraf \"dist/public\"",
    "copy-deps": "cpx \"*{package.json,package-lock.json,yarn.lock}\" \"dist/functions\" -C",
    "install-deps": "cd \"dist/functions\" && npm i"
  }

when I run firebase in local and i fire the URL "http://localhost:5000/" ---> Hello
then the output will be "hello", but when I fire the URL "http://localhost:5000/berlin/clinic" then the page does not respond it went into the infinite loop I don't know what to do

if anyone can help me solve this.

if you need more information just let me know