Apex domains cannot have CNAME records.
Question and response
Question
dig gertsecards.com. NS
Answer
gertsecards.com. 5 NS ns-1993.awsdns-57.co.uk.
gertsecards.com. 5 NS ns-405.awsdns-50.com.
gertsecards.com. 5 NS ns-276.awsdns-34.com.
gertsecards.com. 5 NS ns-670.awsdns-19.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0