Apex domains cannot have CNAME records.
Question and response
Question
dig inotel.pl. NS
Answer
inotel.pl. 5 NS dns1.tld.pl.
inotel.pl. 5 NS ns3.inotel.pl.
inotel.pl. 5 NS ns1.inotel.pl.
inotel.pl. 5 NS dns2.tld.pl.
inotel.pl. 5 NS ns2.inotel.pl.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0