How to remove # from url in MEAN

I have a website which having front end and back end. I have stored my front end files in client folder. and back end files in admin folder. I have removed # tag from front end url.

by adding

$locationProvider.html5Mode(true); 

in my client app.js file

and

<base href="/">

added in client index.html file

Same thing I added in admin folder file also in index.html I added

<base href="/admin">

but still its not working

here is my server.js file

var express = require('express');
var bodyParser = require('body-parser');
var app = express();

var path = require('path');

var session = require('express-session');
var mongoose = require('mongoose');

mongoose.connect('mongodb://localhost/edb');

app.all('/', function(req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "X-Requested-With");
    next()
  });

app.use(session({secret: 'keyboard cat', cookie: { maxAge: 60000 }, resave: true, saveUninitialized: true }))


app.use('/', express.static('app', { redirect: false }));


app.get('/', function (req, res, next) {
    res.sendFile(path.resolve('client/index.html'));
});

I have tried adding this at the server.js file

app.get('/admin', function (req, res, next) {
        res.sendFile(path.resolve('admin/index.html'));
    });

but its taking to clent index.html file

Please give me a solution

thank you

via Athi