dev.intros.gr has no NS records.
NS records for this zone are defined at intros.gr.
NS records for this zone are defined at intros.gr.
Question and response
Question
dig dev.intros.gr. NS
Answer
The response has no answer records.
Authority
intros.gr. 1800 SOA ashton.ns.cloudflare.com. dns.cloudflare.com. 2397464435 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0