Why am I seeing a 502 Bad Gateway error on my site?

I’m not sure what the issue is but I was working on a site and everything was going fine then out of nowhere I lost access and now it keeps saying 502 Bad Gateway. Can Shopify help with this or can someone let me know what’s going on?

Also, I already cleared my cache. Still not working.

UPDATE: Now it’s saying 504 Gateway Time-Out