Apex domains cannot have CNAME records.
Question and response
Question
dig head-cased.com. NS
Answer
head-cased.com. 5 NS ns-1089.awsdns-08.org.
head-cased.com. 5 NS ns-569.awsdns-07.net.
head-cased.com. 5 NS ns-201.awsdns-25.com.
head-cased.com. 5 NS ns-547.awsdns-04.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0