does not show any output or error in indexes of node

This is my code for creating an index and finding the data using MongoDB, but it doesn’t show any output or error.

I already install mongose, mongo-client, plus it does not contain any URL errors. Where did it go wrong?

const MongoClient = require('mongodb').MongoClient;

// Connection URL and database name
const url = 'mongodb://127.0.0.1:27017';
const dbName = 'myproject';

// Use connect method to connect to the server
function connectDB(){

  MongoClient.connect(url, function(err, client) {
    if (err) {
      console.error('Failed to connect to the MongoDB server:', err);
      return;
    }
    console.log("Connected successfully to server");
  
    const db = client.db(dbName);
    const collection = db.collection('mycollection');
  
    // Create an index on the 'name' field
    collection.createIndex({name: Dev,age : 20}, function(err, result) {
      if (err) {
        console.error('Failed to create index:', err);
        console.log(result);
        client.close();
        return;
      }
      // Find all documents where the 'name' field is equal to 'John'
      collection.find({name: 'dev'}).toArray(function(err, docs) {
        if (err) {
          console.error('Failed to retrieve documents:', err);
          client.close();
          return;
        }
        console.log(docs);
        client.close();
      });
    });
  });
}

connectDB();