Apex domains cannot have CNAME records.
Question and response
Question
dig netskope.com. NS
Answer
netskope.com. 5 NS ns1.netskope.com.
netskope.com. 5 NS ns2.netskope.com.
netskope.com. 5 NS ns3.netskope.com.
netskope.com. 5 NS ns4.netskope.com.
Authority
The response has no authority records.
Additional
ns1.netskope.com. 5 A 75.98.6.20
ns2.netskope.com. 5 A 75.98.6.21
ns3.netskope.com. 5 A 163.116.135.227
ns4.netskope.com. 5 A 163.116.193.198
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0