inversify/InversifyJS

I am trying to reuse the MongoDB inversify-express-example but without using the inversify-express-utils (removing the controller decorators and the InversifyExpressServer from the app) I am having a problem to register the container.

In /controller/user.ts

Import { injectable, inject } from 'inversify';
import { User } from '../models/user';
//I created a an interface for the UserService
import { IUserService } from '../service/user';
import { TYPES } from '../constant/types';

@injectable()
export class UserController{
  private userService: IUserService;
  constructor(@inject(TYPES.IUserService) userService: IUserService) 
  {
    this.userService = userService;
  }
  public getUsers(): Promise<User[]> {
    return this.userService.getUsers();
  }
...

Created /controller/toute.ts

import { Router } from 'express'
import { container } from '../di'
import { TYPES } from '../constant/types'
import { UserController } from './user'

const routes = Router()
 const controller: UserController = container.get<UserController>(TYPES.UserController)

routes.get('/users', controller.getUsers)
// router.post('/users', controller.Create)
// router.get('/users/:id', controller.FindOne)
// router.put('/users/:id', controller.Update)
// router.delete('/users/:id', controller.Delete)
export { routes }

Created a /di/index.ts

import { TYPES } from '../constant/types'
import { Container } from 'inversify'
import { UserController }  from '../controller/user'
import { UserService, IUserService } from '../service/user'
import { MongoDBClient } from '../utils/mongodb/client'
let container = new Container()
container.bind<MongoDBClient>(TYPES.MongoDBClient).to(MongoDBClient)
container.bind<IUserService>(TYPES.IUserService).to(UserService)
container.bind<UserController>(TYPES.UserController).to(UserController)
export { container }

Modified the /service/user.ts

import { inject, injectable } from 'inversify';
import { MongoDBClient } from '../utils/mongodb/client';
import { User } from '../models/user';
import { TYPES } from '../constant/types';
import { publishToQueue } from '../queueevents/mqpublishingservice'

export  interface IUserService {
  newUser: (user: User) => Promise<User>
  getUsers: () => Promise< User[]>
  getUser: (id: string) => Promise<User>
  updateUser: (id: string, user: User)=> Promise<User>
  deleteUser: (id: string) => Promise<any>
}
@injectable()
export class UserService implements IUserService{
  private mongoClient: MongoDBClient;
  constructor(
    @inject(TYPES.MongoDBClient) mongoClient: MongoDBClient
  ) {
    //console.log(`UserService:constructor: ${JSON.stringify(mongoClient)}`)
    this.mongoClient = mongoClient;
  }

  public getUsers(): Promise<User[]> {
    return new Promise<User[]>((resolve, reject) => {
      this.mongoClient.find('user', {}, (error, data: User[]) => {
        resolve(data);
      });
    });
  }

And finally changed the bootstrap.ts to

import 'reflect-metadata'
import './di'
import * as express from 'express'
import * as cors from 'cors'
import { routes} from './controller/router'
const app = express()
app.use(express.json()) // Recognize the incoming Request Object as a JSON Object
app.use(express.urlencoded({ extended: true })) //  Recognize the incoming Request Object as strings or arrays
app.use(cors()) // Enable All CORS Requests
app.use(routes);
app.listen(3001);
console.log('Server started on port 3001 :)')

exports = module.exports = app;

But I get the error

TypeError: Cannot read property 'userService' of undefined
at UserController.getUsers (\MongoDB\controller\user.ts:23:17)

Which is at (/controller/user.ts)
return this.userService.getUsers()

Do not know if somebody already solved it ... I am new to this environment... Thank you