My domain is not working & getting error 502

You wrote 502, and your screenshot says 522. Are you seeing both or is it just a typo?

A 522 error typically happens when Cloudflare requests to the origin (your webserver) get blocked. Review the suggestions in this Community Tip for troubleshooting ideas.

Just in case:

The 502/504 errors are caused by a problem connecting to an upstream server - meaning your server is trying to initiate a process and this fails to work as expected or times out. In most cases of 502 / 504 errors, back-end servers are not communicating correctly. When this happens, you will see color page with Cloudflare branding and the Error 502 Bad Gateway or Error 504 Gateway Timeout. Review this Community Tip for fixing 502 or 504 gateway errors.