sender20.mlgnr.com has no NS records.
NS records for this zone are defined at mlgnr.com.
NS records for this zone are defined at mlgnr.com.
Question and response
Question
dig sender20.mlgnr.com. NS
Answer
The response has no answer records.
Authority
mlgnr.com. 300 SOA ns3-l2.nic.ru. admin.mlgnr.com. 2020073312 10800 3600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0