Apex domains cannot have CNAME records.
Question and response
Question
dig linuramoto.info. NS
Answer
linuramoto.info. 5 NS ns2.linuramoto.info.
linuramoto.info. 5 NS ns1.linuramoto.info.
Authority
The response has no authority records.
Additional
ns1.linuramoto.info. 5 A 137.74.113.57
ns2.linuramoto.info. 5 A 5.196.58.111
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0