Apex domains cannot have CNAME records.
Question and response
Question
dig squalo.io. NS
Answer
squalo.io. 4 NS ns2.itars.eu.
squalo.io. 4 NS ns1.itars.eu.
Authority
The response has no authority records.
Additional
ns1.itars.eu. 3 A 5.157.72.1
ns2.itars.eu. 3 A 91.185.193.219
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0