Apex domains cannot have CNAME records.
Question and response
Question
dig energa.pl. NS
Answer
energa.pl. 4 NS ns3.ps.oktawave.com.
energa.pl. 4 NS ns1.ps.oktawave.com.
energa.pl. 4 NS ns2.ps.oktawave.com.
Authority
The response has no authority records.
Additional
ns1.ps.oktawave.com. 4 A 193.200.66.215
ns2.ps.oktawave.com. 4 A 185.64.29.109
ns3.ps.oktawave.com. 4 A 176.119.32.123
ns2.ps.oktawave.com. 4 AAAA 2a03:d60:2:201:250:56ff:fe98:ddb5
ns3.ps.oktawave.com. 4 AAAA 2a03:d60:0:2:250:56ff:fe89:5b29
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0