Passport: Authentication not Working - node.js

Question

I am new to NodeJS. I am made a basic CRUD app with authentication using express. Sign up was successful but login is not successful.I am using passport and bcryptjs for authentication.
Here is home route. As index is called automatically so this is not getting called. For other routes it works only if manually pass the function ensureAuthenticated to their parameters just like below. I want it to work for all endpoints without manually doing so.
app.get("/", ensureAuthenticated, function (req, res) {
res.render('index');
});
Below is the login functionality.
app.get("/login", function (req, res) {
const loginPath = path.join(__dirname, '/login.html');
res.sendFile(loginPath);
});
passport.use(new localStrategy({
usernameField: 'adminUsername',
passwordField: 'password',
session: false
},
function (adminUsername, password, done) {
Admin.getAdminByAdminUsername(adminUsername, function (err, admin) {
if (err) throw err;
console.log('getAdmin called');
if (!admin) {
console.log('Admin Not Found');
return done(null, false);
}
Admin.comparePassword(password, admin.password, function (err, isMatch) {
console.log('comparePassword called');
if (err) throw err;
if (isMatch) {
return done(null, admin);
} else {
console.log('Wrong Password!');
return done(null, false);
}
});
});
}));
passport.serializeUser(function (admin, done) {
done(null, admin.id);
});
passport.deserializeUser(function (id, done) {
Admin.getAdminById(id, function (err, admin) {
done(err, admin);
console.log('findById called');
});
});
app.post('/login', passport.authenticate('local', {
failureRedirect: '/login'}), function(req, res){
console.log('login called');
res.redirect('/');
});
app.get('/logout', function(req,res){
req.logout();
res.redirect('/login');
});
function ensureAuthenticated(req, res, next){
if (req.isAuthenticated()) {
return next();
} else {
res.redirect('/login');
}
}
The problem is even without authentication, I still have access via URL endpoints.
Here is the Admin schema file.
const mongoose = require("mongoose");
const bcrypt = require('bcryptjs');
const schema = new mongoose.Schema({
adminEmail: {
type: String,
unique: true,
required: true
},
adminUsername:{
type: String,
unique: true,
required: true
},
password:{
type: String,
required: true
}
});
const Admin = mongoose.model('Admin', schema);
module.exports = Admin;
module.exports.getAdminByAdminUsername = function (adminUsername, callback) {
const query = {adminUsername: adminUsername};
Admin.findOne(query, callback);
}
module.exports.getAdminById = function (adminId, callback) {
Admin.findById(adminId, callback);
}
module.exports.comparePassword = function (password, hash, callback) {
bcrypt.compare(password, hash, function (err, isMatch) {
if (err) throw err;
callback(null, isMatch);
});
}