Apex domains cannot have CNAME records.
Question and response
Question
dig ebir.si. NS
Answer
ebir.si. 5 NS ns3.naliniji.com.
ebir.si. 5 NS ns2.naliniji.com.
ebir.si. 5 NS ns1.naliniji.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0