Apex domains cannot have CNAME records.
Question and response
Question
dig kinghost.com.br. NS
Answer
kinghost.com.br. 5 NS dns5.kinghost.com.br.
kinghost.com.br. 5 NS dns4.kinghost.com.br.
kinghost.com.br. 5 NS dns1.kinghost.com.br.
kinghost.com.br. 5 NS dns3.kinghost.com.br.
kinghost.com.br. 5 NS dns2.kinghost.com.br.
kinghost.com.br. 5 NS dns6.kinghost.com.br.
Authority
The response has no authority records.
Additional
dns1.kinghost.com.br. 5 A 162.159.24.170
dns2.kinghost.com.br. 5 A 162.159.25.249
dns3.kinghost.com.br. 5 A 162.159.24.144
dns4.kinghost.com.br. 5 A 162.159.25.20
dns5.kinghost.com.br. 5 A 162.159.24.188
dns6.kinghost.com.br. 5 A 162.159.25.93
dns1.kinghost.com.br. 5 AAAA 2400:cb00:2049:1:0:0:a29f:18aa
dns2.kinghost.com.br. 5 AAAA 2400:cb00:2049:1:0:0:a29f:19f9
dns3.kinghost.com.br. 5 AAAA 2400:cb00:2049:1:0:0:a29f:1890
dns4.kinghost.com.br. 5 AAAA 2400:cb00:2049:1:0:0:a29f:1914
dns5.kinghost.com.br. 5 AAAA 2400:cb00:2049:1:0:0:a29f:18bc
dns6.kinghost.com.br. 5 AAAA 2400:cb00:2049:1:0:0:a29f:195d
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0