Validation timed out for AWS certificate manager

Please refer to the following page to check if CNAME records can be referenced correctly.

https://repost.aws/knowledge-center/acm-certificate-pending-validation

I had added CNAME records to my domain DNS ,corresponding to the two above

It's not CNAMEs for dgnurse.com & www.dgnurse.com that should be added, rather it's a record whose name is (what looks like) a random string of characters, and whose value is a TXT record composed of another string of random characters. Examples of what this might look like are here https://docs.aws.amazon.com/acm/latest/userguide/dns-validation.html#cnames-overview

If the domain is administered by Route 53 then this can be done automatically, there will be a link in the ACM Request saying Click here to create these records (or something like that). If Route 53 isn't the DNS provider then these will need to be created manually on the DNS provider's side (AWS can't do that, you need to do that yourself).

Once these (random) CNAMEs are created, it proves to ACM that you administer the domain for which the certificates are to be issued. ACM will then issue the certificate for (in this case) dgnurse.com & www.dgnurse.com, following which you can create whatever type of record (A, ALIAS, CNAME, etc.) it is that you need to.