Apex domains cannot have CNAME records.
Question and response
Question
dig dkm.ua. NS
Answer
dkm.ua. 1 NS ns2.dkm.ua.
dkm.ua. 1 NS ns1.dkm.ua.
Authority
The response has no authority records.
Additional
ns1.dkm.ua. 1 A 193.151.13.5
ns2.dkm.ua. 1 A 193.151.12.8
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0