Apex domains cannot have CNAME records.
Question and response
Question
dig abitek.com.ua. NS
Answer
abitek.com.ua. 5 NS nsb3.srv53.org.
abitek.com.ua. 5 NS nsa2.srv53.org.
abitek.com.ua. 5 NS nsb1.srv53.com.
abitek.com.ua. 5 NS nsd4.srv53.net.
abitek.com.ua. 5 NS nsa1.srv53.net.
abitek.com.ua. 5 NS nsc1.srv53.com.
abitek.com.ua. 5 NS nsa2.srv53.com.
abitek.com.ua. 5 NS nsc3.srv53.net.
abitek.com.ua. 5 NS nsd1.srv53.com.
abitek.com.ua. 5 NS nsb3.srv53.net.
abitek.com.ua. 5 NS nsc1.srv53.org.
abitek.com.ua. 5 NS nsd3.srv53.org.
Authority
The response has no authority records.
Additional
nsa1.srv53.net. 5 A 5.39.10.94
nsb1.srv53.com. 5 A 135.181.9.147
nsc1.srv53.com. 5 A 78.27.225.73
nsc1.srv53.org. 5 A 78.27.225.71
nsd1.srv53.com. 5 A 89.184.64.99
nsd3.srv53.org. 5 A 89.184.64.96
nsa1.srv53.net. 5 AAAA 2001:41d0:203:dee4:5:39:10:94
nsb1.srv53.com. 5 AAAA 2a01:4f9:4a:530c:181:9:147:2
nsc1.srv53.com. 5 AAAA 2a02:2279:0:1201:78:27:225:73
nsc1.srv53.org. 5 AAAA 2a02:2279:0:1201:78:27:225:71
nsd1.srv53.com. 5 AAAA 2a02:2278:70eb:298:89:184:64:99
nsd3.srv53.org. 5 AAAA 2a02:2278:70eb:298:89:184:64:96
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0