Apex domains cannot have CNAME records.
Question and response
Question
dig denpla.net. NS
Answer
denpla.net. 5 NS ns-822.awsdns-38.net.
denpla.net. 5 NS ns-584.awsdns-09.net.
denpla.net. 5 NS ns-600.awsdns-11.net.
denpla.net. 5 NS ns-1452.awsdns-53.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0