Apex domains cannot have CNAME records.
Question and response
Question
dig ceabs.com.br. NS
Answer
ceabs.com.br. 5 NS ns-1164.awsdns-17.org.
ceabs.com.br. 5 NS ns-107.awsdns-13.com.
ceabs.com.br. 5 NS ns-953.awsdns-55.net.
ceabs.com.br. 5 NS ns-1912.awsdns-47.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0