Apex domains cannot have CNAME records.
Question and response
Question
dig antevenio.com. NS
Answer
antevenio.com. 5 NS ns01.prosodie.es.
antevenio.com. 5 NS ns1.antevenio.com.
antevenio.com. 5 NS ns2.antevenio.com.
antevenio.com. 5 NS ns02.prosodie.es.
Authority
The response has no authority records.
Additional
ns1.antevenio.com. 5 A 62.97.140.30
ns2.antevenio.com. 5 A 62.97.140.31
ns01.prosodie.es. 5 A 212.101.72.98
ns02.prosodie.es. 5 A 62.97.128.173
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0