Apex domains cannot have CNAME records.
Question and response
Question
dig autoalertor.com. NS
Answer
autoalertor.com. 5 NS ns-1426.awsdns-50.org.
autoalertor.com. 5 NS ns-1304.awsdns-35.org.
autoalertor.com. 5 NS ns-368.awsdns-46.com.
autoalertor.com. 5 NS ns-405.awsdns-50.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0