Apex domains cannot have CNAME records.
Question and response
Question
dig netos.com. NS
Answer
netos.com. 2 NS ns-3.nuoz.net.
netos.com. 2 NS ns-1.nuoz.net.
netos.com. 2 NS ns-2.nuoz.net.
Authority
The response has no authority records.
Additional
ns-1.nuoz.net. 2 A 216.251.100.50
ns-2.nuoz.net. 2 A 66.228.212.94
ns-3.nuoz.net. 2 A 206.63.32.225
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0