Apex domains cannot have CNAME records.
Question and response
Question
dig inventio.it. NS
Answer
inventio.it. 2 NS ns1-08.azure-dns.com.
inventio.it. 2 NS ns3-08.azure-dns.org.
inventio.it. 2 NS ns2-08.azure-dns.net.
inventio.it. 2 NS ns4-08.azure-dns.info.
Authority
The response has no authority records.
Additional
ns1-08.azure-dns.com. 2 A 13.107.236.8
ns2-08.azure-dns.net. 2 A 150.171.21.8
ns3-08.azure-dns.org. 2 A 204.14.183.8
ns4-08.azure-dns.info. 2 A 208.84.5.8
ns1-08.azure-dns.com. 2 AAAA 2603:1061:0:700:0:0:0:8
ns2-08.azure-dns.net. 2 AAAA 2620:1ec:8ec:700:0:0:0:8
ns3-08.azure-dns.org. 2 AAAA 2a01:111:4000:700:0:0:0:8
ns4-08.azure-dns.info. 2 AAAA 2620:1ec:bda:700:0:0:0:8
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0