Apex domains cannot have CNAME records.
Question and response
Question
dig ukrtel.net. NS
Answer
ukrtel.net. 5 NS ns2-dp.ukrtel.net.
ukrtel.net. 5 NS expert.ukrtel.net.
ukrtel.net. 5 NS ns2.ukrtel.net.
ukrtel.net. 5 NS expert-dp.ukrtel.net.
ukrtel.net. 5 NS ns1-01.azure-dns.com.
ukrtel.net. 5 NS ns2-01.azure-dns.net.
ukrtel.net. 5 NS ns4-01.azure-dns.info.
ukrtel.net. 5 NS ns3-01.azure-dns.org.
Authority
The response has no authority records.
Additional
expert.ukrtel.net. 5 A 195.5.6.10
ns1-01.azure-dns.com. 5 A 13.107.236.1
ns2-01.azure-dns.net. 5 A 150.171.21.1
ns3-01.azure-dns.org. 5 A 204.14.183.1
expert-dp.ukrtel.net. 5 A 213.179.228.2
ns1-01.azure-dns.com. 5 AAAA 2603:1061:0:700:0:0:0:1
ns2-01.azure-dns.net. 5 AAAA 2620:1ec:8ec:700:0:0:0:1
ns3-01.azure-dns.org. 5 AAAA 2a01:111:4000:700:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0