Apex domains cannot have CNAME records.
Question and response
Question
dig ukrnames.com. NS
Answer
ukrnames.com. 2 NS ns1.ukrnames.com.
ukrnames.com. 2 NS ns4.ukrnames.ua.
ukrnames.com. 2 NS ns3.ukrnames.com.
ukrnames.com. 2 NS ns2.ukrnames.com.
Authority
The response has no authority records.
Additional
ns1.ukrnames.com. 2 A 104.131.20.233
ns2.ukrnames.com. 2 A 195.123.1.2
ns3.ukrnames.com. 2 A 37.59.88.192
ns4.ukrnames.ua. 2 A 195.123.192.222
ns1.ukrnames.com. 2 AAAA 2604:a880:800:10:0:0:68:2001
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0