Apex domains cannot have CNAME records.
Question and response
Question
dig server.martynas.it. NS
Answer
server.martynas.it. 5 NS ns2.martynas.it.
server.martynas.it. 5 NS ns1.martynas.it.
Authority
The response has no authority records.
Additional
ns1.martynas.it. 5 A 157.90.223.112
ns2.martynas.it. 5 A 193.46.84.152
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0