Apex domains cannot have CNAME records.
Question and response
Question
dig securityeducation.com. NS
Answer
securityeducation.com. 5 NS ns-1793.awsdns-32.co.uk.
securityeducation.com. 5 NS ns-609.awsdns-12.net.
securityeducation.com. 5 NS ns-475.awsdns-59.com.
securityeducation.com. 5 NS ns-1254.awsdns-28.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0