zone to registered domain mapping

Hi. I have domain registered with AWS and lets say example.com

There is a NS and SOA record, however a dig or nslookup isn't currently resolving and think related to
https://repost.aws/questions/QULvn-o4npQQOV7y_iUCFNFQ/ns-and-soa-records-in-my-host-zone-but-cant-find-them-when-i-use-dig (and now updated for example.com but waiting for it to propagate)

So what about having a sub-domain? i.e . I require test.example.com I have this under the hosted zones, but how do I now link this to registered domains or rather what exactly do I need to do to create sub-domain?

BTW, in both cased, AWS hosts for the domains example.com and test.example.com are external to AWS and trying to create a SSL that can be used - however in first instance need example.com and test.example.com to at least resolve.

Thanks Mark