Apex domains cannot have CNAME records.
Question and response
Question
dig sfsfsef.com. NS
Answer
sfsfsef.com. 4 NS ns-917.awsdns-50.net.
sfsfsef.com. 4 NS ns-273.awsdns-34.com.
sfsfsef.com. 4 NS ns-761.awsdns-31.net.
sfsfsef.com. 4 NS ns-1510.awsdns-60.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0