Apex domains cannot have CNAME records.
Question and response
Question
dig domreg.lt. NS
Answer
domreg.lt. 5 NS ns2.domreg.lt.
domreg.lt. 5 NS ns1.domreg.lt.
domreg.lt. 5 NS nsa.domreg.lt.
Authority
The response has no authority records.
Additional
ns1.domreg.lt. 5 A 185.150.40.44
ns2.domreg.lt. 5 A 83.171.8.8
nsa.domreg.lt. 5 A 185.150.42.1
ns1.domreg.lt. 5 AAAA 2a07:ab40:0:0:0:0:0:44
ns2.domreg.lt. 5 AAAA 2001:778:0:8:0:0:0:8
nsa.domreg.lt. 5 AAAA 2a07:ab42:0:0:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0