Didn’t get response from the query when creating DB Pool. Nodejs Mysql

Earlier I am working with the single connection but now I am trying to create a DB Pool in Nodejs using Mysql.

I am following the Single Pattern or Class-Based Pattern to create a query and other operations

Earlier Configuration (Everything working fine)

const connection = mysql.createConnection({
  host: dbConfig.HOST,
  user: dbConfig.USER,
  password: dbConfig.PASSWORD,
  database: dbConfig.DB
});

connection.connect();
connection.query("SET AUTOCOMMIT=false;", (err) => {
  if(err){
    console.log(err)
    console.log("Couldn't set auto commit to false")
  }else{
    console.log("AutoCommit set to false")
  }
});

function query(sql, params, autorollback) {
  return new Promise((resolve, reject) => {
    //let currentTime = new Date().valueOf();
    let query = connection.query(sql, params, (err, resp) => {
      if(err && autorollback) {
        return resolve(rollback(err));
      }
      else if (err) {
        console.log(err)
        return reject(err);
      }
      //console.log("Time Taken: ", new Date().valueOf() - currentTime, "n", query.sql);
      //console.log(resp);
      resolve(resp);
    });
  });
}

Create Pool Configuration (Didn’t get the response from the query)

const connection = mysql.createPool({
    host: dbConfig.HOST,
    user: dbConfig.USER,
    password: dbConfig.PASSWORD,
    database: dbConfig.DB,
    connectionLimit: 4,
});

connection.getConnection(function (err, conn) {
    conn.query("SET AUTOCOMMIT=false;", (err) => {
        if (err) {
            console.log(err)
            console.log("Couldn't set auto commit to false")
        } else {
            console.log("AutoCommit set to false")
        }
    });
});

function query(sql, params, autorollback) {
    console.log(sql)
    return new Promise((resolve, reject) => {
        //let currentTime = new Date().valueOf();
        connection.getConnection(function (err, conn) {

            if (err) {
                console.log(err)
                return reject(err);
            }
            let query = conn.query(sql, params, (err, resp) => {
                console.log(sql)
                if (err && autorollback) {
                    return resolve(rollback(err));
                }
                else if (err) {
                    console.log(err)
                    return reject(err);
                }
                //console.log("Time Taken: ", new Date().valueOf() - currentTime, "n", query.sql);
                //console.log(resp);

                resolve(resp);
                conn.release();
            });
        })
    });
}