Apex domains cannot have CNAME records.
Question and response
Question
dig developingdog.com. NS
Answer
developingdog.com. 3 NS ns-1214.awsdns-23.org.
developingdog.com. 3 NS ns-1463.awsdns-54.org.
developingdog.com. 3 NS ns-1904.awsdns-46.co.uk.
developingdog.com. 3 NS ns-740.awsdns-28.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0