Apex domains cannot have CNAME records.
Question and response
Question
dig powiatjanowski.pl. NS
Answer
powiatjanowski.pl. 5 NS ns2.d9tn8.seohost.cloud.
powiatjanowski.pl. 5 NS ns1.d9tn8.seohost.cloud.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0