_acme-challenge.staging.oml.RU has no NS records.
NS records for this zone are defined at staging.oml.RU.
NS records for this zone are defined at staging.oml.RU.
Question and response
Question
dig _acme-challenge.staging.oml.RU. NS
Answer
The response has no answer records.
Authority
staging.oml.RU. 783 SOA ns.megagroup.RU. dnsmaster.megagroup.RU. 993036 21600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0