Apex domains cannot have CNAME records.
Question and response
Question
dig byteopt.com. NS
Answer
byteopt.com. 5 NS ns1.byteopt.com.
byteopt.com. 5 NS earth.ns.byteopt.com.
byteopt.com. 5 NS pns.speednet.bg.
byteopt.com. 5 NS ns2.byteopt.com.
byteopt.com. 5 NS mars.ns.byteopt.com.
Authority
The response has no authority records.
Additional
ns1.byteopt.com. 5 A 85.187.45.11
ns2.byteopt.com. 5 A 151.237.23.11
mars.ns.byteopt.com. 5 A 151.237.23.11
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0