_acme-challenge.testedomainsf.oi.com.br has no NS records.
NS records for this zone are defined at oi.com.br.
NS records for this zone are defined at oi.com.br.
Question and response
Question
dig ac.69437655fddfd7ea07b09b8e1e2784d1.testedomainsf.oi.com.br.validate-akdv.net. NS
Answer
The response has no answer records.
Authority
ac.69437655fddfd7ea07b09b8e1e2784d1.testedomainsf.oi.com.br.validate-akdv.net. 3600 SOA validate-akdv.net. hostmaster\@validate-akdv.net. 1 7200 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0