Apex domains cannot have CNAME records.
Question and response
Question
dig anpdm.com. NS
Answer
anpdm.com. 5 NS ns-662.awsdns-18.net.
anpdm.com. 5 NS ns-1425.awsdns-50.org.
anpdm.com. 5 NS ns-1632.awsdns-12.co.uk.
anpdm.com. 5 NS ns-100.awsdns-12.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0