Apex domains cannot have CNAME records.
Question and response
Question
dig apartmani-racanovic.com. NS
Answer
apartmani-racanovic.com. 5 NS ns-11.awsdns-01.com.
apartmani-racanovic.com. 5 NS ns-164.awsdns-20.com.
apartmani-racanovic.com. 5 NS ns-515.awsdns-00.net.
apartmani-racanovic.com. 5 NS ns-732.awsdns-27.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0