Apex domains cannot have CNAME records.
Question and response
Question
dig dkm.dp.ua. NS
Answer
dkm.dp.ua. 5 NS ns2.alba.dp.ua.
dkm.dp.ua. 5 NS ns.alba.dp.ua.
Authority
The response has no authority records.
Additional
ns2.alba.dp.ua. 5 A 193.151.12.8
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0