Apex domains cannot have CNAME records.
Question and response
Question
dig heanworld.com. NS
Answer
heanworld.com. 5 NS ns-1128.awsdns-13.org.
heanworld.com. 5 NS ns-753.awsdns-30.net.
heanworld.com. 5 NS ns-1074.awsdns-06.org.
heanworld.com. 5 NS ns-1853.awsdns-39.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0