Apex domains cannot have CNAME records.
Question and response
Question
dig ddm.adv.br. NS
Answer
ddm.adv.br. 5 NS ns1.ddm.adv.br.
ddm.adv.br. 5 NS ns2.ddm.adv.br.
Authority
The response has no authority records.
Additional
ns1.ddm.adv.br. 5 A 162.214.155.190
ns2.ddm.adv.br. 5 A 162.214.103.142
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0