Apex domains cannot have CNAME records.
Question and response
Question
dig buycnb.com. NS
Answer
buycnb.com. 5 NS ns-507.awsdns-63.com.
buycnb.com. 5 NS ns-1256.awsdns-29.org.
buycnb.com. 5 NS ns-12.awsdns-01.com.
buycnb.com. 5 NS ns-1060.awsdns-04.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0