let conn = new XMLHttpRequest(); conn.onreadystatecgange... This is not responding don't know why Pls can you guide me?

Question

Using Ajax to run my php file background but I realised that it's not working the onreadysrate and open() are not working except the let conn = new XMLHttpRequest(). I need you guys attention so that I can move on with my studies

Answer 1

can you post the codes ?