Apex domains cannot have CNAME records.
Question and response
Question
dig com4datacenter.com.br. NS
Answer
com4datacenter.com.br. 1 NS ns2.com4datacenter.com.br.
com4datacenter.com.br. 1 NS ns1.com4datacenter.com.br.
Authority
The response has no authority records.
Additional
ns1.com4datacenter.com.br. 1 A 189.90.130.11
ns2.com4datacenter.com.br. 1 A 189.90.131.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0