Apex domains cannot have CNAME records.
Question and response
Question
dig coolgiftspromo.com. NS
Answer
coolgiftspromo.com. 5 NS ns-1813.awsdns-34.co.uk.
coolgiftspromo.com. 5 NS ns-862.awsdns-43.net.
coolgiftspromo.com. 5 NS ns-511.awsdns-63.com.
coolgiftspromo.com. 5 NS ns-984.awsdns-59.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0