Apex domains cannot have CNAME records.
Question and response
Question
dig voithia.org. NS
Answer
voithia.org. 5 NS ns-1738.awsdns-25.co.uk.
voithia.org. 5 NS ns-701.awsdns-23.net.
voithia.org. 5 NS ns-986.awsdns-59.net.
voithia.org. 5 NS ns-1092.awsdns-08.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0