Apex domains cannot have CNAME records.
Question and response
Question
dig dolca.net. NS
Answer
dolca.net. 5 NS ns.wedos.com.
dolca.net. 5 NS ns.wedos.cz.
dolca.net. 5 NS ns1.dolca.net.
dolca.net. 5 NS ns.wedos.net.
Authority
The response has no authority records.
Additional
ns1.dolca.net. 5 A 82.209.47.178
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0