Apex domains cannot have CNAME records.
Question and response
Question
dig it.com. NS
Answer
it.com. 5 NS ns2.it.com.
it.com. 5 NS ns1.it.com.
it.com. 5 NS ns3.it.com.
Authority
The response has no authority records.
Additional
ns1.it.com. 5 A 162.159.8.93
ns2.it.com. 5 A 162.159.9.224
ns3.it.com. 5 A 162.159.10.96
ns1.it.com. 5 AAAA 2400:cb00:2049:1:0:0:a29f:85d
ns2.it.com. 5 AAAA 2400:cb00:2049:1:0:0:a29f:9e0
ns3.it.com. 5 AAAA 2400:cb00:2049:1:0:0:a29f:a60
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0