Apex domains cannot have CNAME records.
Question and response
Question
dig voks.ua. NS
Answer
voks.ua. 4 NS ns-ua.wnet.pro.
voks.ua. 4 NS ns-pl.wnet.pro.
voks.ua. 4 NS ns-us.wnet.pro.
Authority
The response has no authority records.
Additional
ns-pl.wnet.pro. 4 A 193.16.47.79
ns-ua.wnet.pro. 4 A 91.202.109.31
ns-us.wnet.pro. 4 A 185.38.210.30
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0