Apex domains cannot have CNAME records.
Question and response
Question
dig litvpn.com. NS
Answer
litvpn.com. 4 NS ns3.dnsexit.com.
litvpn.com. 4 NS ns2.dnsexit.com.
litvpn.com. 4 NS ns1.dnsexit.com.
litvpn.com. 4 NS ns4.dnsexit.com.
Authority
The response has no authority records.
Additional
ns1.dnsexit.com. 4 A 31.14.40.88
ns2.dnsexit.com. 4 A 173.208.164.34
ns3.dnsexit.com. 4 A 204.12.192.106
ns4.dnsexit.com. 4 A 107.150.58.186
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0