Apex domains cannot have CNAME records.
Question and response
Question
dig inmoo.net. NS
Answer
inmoo.net. 5 NS ns-804.awsdns-36.net.
inmoo.net. 5 NS ns-1074.awsdns-06.org.
inmoo.net. 5 NS ns-1538.awsdns-00.co.uk.
inmoo.net. 5 NS ns-215.awsdns-26.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0