Apex domains cannot have CNAME records.
Question and response
Question
dig btz77.com. NS
Answer
btz77.com. 5 NS ns-1157.awsdns-16.org.
btz77.com. 5 NS ns-1695.awsdns-19.co.uk.
btz77.com. 5 NS ns-1826.awsdns-36.co.uk.
btz77.com. 5 NS ns-381.awsdns-47.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0