Apex domains cannot have CNAME records.
Question and response
Question
dig gov.hu. NS
Answer
gov.hu. 5 NS adns0.gov.hu.
gov.hu. 5 NS adns2.gov.hu.
gov.hu. 5 NS adns1.gov.hu.
Authority
The response has no authority records.
Additional
adns0.gov.hu. 5 A 84.206.109.2
adns1.gov.hu. 5 A 84.206.110.2
adns2.gov.hu. 5 A 4.231.229.181
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0