Apex domains cannot have CNAME records.
Question and response
Question
dig armazemdc.com.br. NS
Answer
armazemdc.com.br. 5 NS ns4.armazemdc.com.br.
armazemdc.com.br. 5 NS ns2.armazemdc.com.br.
armazemdc.com.br. 5 NS ns1.armazemdc.com.br.
armazemdc.com.br. 5 NS ns3.armazemdc.com.br.
Authority
The response has no authority records.
Additional
ns1.armazemdc.com.br. 5 A 186.250.186.2
ns2.armazemdc.com.br. 5 A 186.250.186.3
ns3.armazemdc.com.br. 5 A 186.250.185.2
ns4.armazemdc.com.br. 5 A 186.250.185.3
ns1.armazemdc.com.br. 5 AAAA 2804:4d44:adc:a300:0:0:0:31
ns2.armazemdc.com.br. 5 AAAA 2804:4d44:adc:a300:0:0:0:32
ns3.armazemdc.com.br. 5 AAAA 2804:4d44:adc:a300:0:0:0:33
ns4.armazemdc.com.br. 5 AAAA 2804:4d44:adc:a300:0:0:0:34
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0