Apex domains cannot have CNAME records.
Question and response
Question
dig hmx.hu. NS
Answer
hmx.hu. 2 NS ns1.hmx.hu.
hmx.hu. 2 NS ns2.hmx.hu.
Authority
The response has no authority records.
Additional
ns1.hmx.hu. 2 A 185.188.56.9
ns2.hmx.hu. 2 A 78.24.184.215
ns1.hmx.hu. 2 AAAA 2a0b:b980:1:0:0:0:0:2
ns2.hmx.hu. 2 AAAA 2a03:8c60:0:0:0:0:0:3
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0