MongoServerError: bad auth : Authentication failed problem when i try to connect with mongodb cluster

Could you please tell me where is the problem or for what reason I got the authentication problem when I try to connect with mongodb atlas,

This is the error message that I got:

 MongoServerError: bad auth : Authentication failed.
    at Connection.onMessage (C:\Users\lenovo\Desktop\dev\mern-tutorial\node_modules\mongodb\lib\cmap\connection.js:207:30)
    at MessageStream.<anonymous> (C:\Users\lenovo\Desktop\dev\mern-tutorial\node_modules\mongodb\lib\cmap\connection.js:60:60)
    at MessageStream.emit (node:events:527:28)
    at processIncomingData (C:\Users\lenovo\Desktop\dev\mern-tutorial\node_modules\mongodb\lib\cmap\message_stream.js:132:20)
    at MessageStream._write (C:\Users\lenovo\Desktop\dev\mern-tutorial\node_modules\mongodb\lib\cmap\message_stream.js:33:9)
    at writeOrBuffer (node:internal/streams/writable:389:12)
    at _write (node:internal/streams/writable:330:10)
    at MessageStream.Writable.write (node:internal/streams/writable:334:10)
    at TLSSocket.ondata (node:internal/streams/readable:754:22)
    at TLSSocket.emit (node:events:527:28) {
  ok: 0,
  code: 8000,
  codeName: 'AtlasError',
  [Symbol(errorLabels)]: Set(1) { 'HandshakeError' }
}
[nodemon] app crashed - waiting for file changes before starting...

I made a .env file that includes the link of mongodb cluster:

MONGO_URI = "mongodb+srv://imen:imen@cluster0.rsyvyrl.mongodb.net/?retryWrites=true&w=majority"

Then in db.js I have this:

   const mongoose = require('mongoose')

const connectDB = async () => {
  try {
    const conn = await mongoose.connect(process.env.MONGO_URI)

    console.log(`MongoDB Connected: ${conn.connection.host}`.cyan.underline)
  } catch (error) {
    console.log(error)
    process.exit(1)
  }
}


module.exports = connectDB

Finally in my entry point which is server.js I have this:

const express = require('express')
const colors = require('colors');
const connectDB = require('./config/db')
const dotenv = require('dotenv').config()
const port= process.env.PORT || 8000
connectDB()


const app = express()


app.listen(port, ()=> console.log(`starting the server on port: ${port}`))