Apex domains cannot have CNAME records.
Question and response
Question
dig contabilizei.com.br. NS
Answer
contabilizei.com.br. 5 NS ns2.aziondns.com.
contabilizei.com.br. 5 NS ns3.aziondns.org.
contabilizei.com.br. 5 NS ns1.aziondns.net.
Authority
The response has no authority records.
Additional
ns1.aziondns.net. 5 A 179.191.160.2
ns2.aziondns.com. 5 A 179.191.161.2
ns3.aziondns.org. 5 A 179.191.162.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0