Certificate Challenge Failed, Connection Refused behind NGINX

I think I found a side issue, it’s now saying no A for 4t.danielr.xyz, check that a DNS record exists (4t is just a test app I have being served). Does this mean that I should add an A record in Namecheap?

I have an A + Dynamic one set up.

This happens even when I try with the normal domain, without the sub.

I apologize if these are stupid questions, this is my first time opening up a server to the internet, I was following this guide for information: dlford.io