Apex domains cannot have CNAME records.
Question and response
Question
dig vh.net.pl. NS
Answer
vh.net.pl. 5 NS ns2.vh.pl.
vh.net.pl. 5 NS ns1.vh.pl.
Authority
The response has no authority records.
Additional
ns1.vh.pl. 4 A 185.17.43.222
ns2.vh.pl. 4 A 193.143.121.155
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0