Apex domains cannot have CNAME records.
Question and response
Question
dig klintsy.org. NS
Answer
klintsy.org. 5 NS ns-578.awsdns-08.net.
klintsy.org. 5 NS ns-584.awsdns-09.net.
klintsy.org. 5 NS ns-1574.awsdns-04.co.uk.
klintsy.org. 5 NS ns-2011.awsdns-59.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0