Apex domains cannot have CNAME records.
Question and response
Question
dig toflip.net. NS
Answer
toflip.net. 5 NS ns-94.awsdns-11.com.
toflip.net. 5 NS ns-1314.awsdns-36.org.
toflip.net. 5 NS ns-21.awsdns-02.com.
toflip.net. 5 NS ns-295.awsdns-36.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0