Apex domains cannot have CNAME records.
Question and response
Question
dig paskov.net. NS
Answer
paskov.net. 5 NS ns.paskov.cz.
paskov.net. 5 NS ns.paskov.eu.
paskov.net. 5 NS ns.paskov.net.
Authority
The response has no authority records.
Additional
ns.paskov.cz. 5 A 161.97.166.226
ns.paskov.net. 5 A 185.175.11.10
ns.paskov.cz. 5 AAAA 2a02:c206:2150:2584:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0