Apex domains cannot have CNAME records.
Question and response
Question
dig supercp.com. NS
Answer
supercp.com. 3 NS ns3.stableserver.net.
supercp.com. 3 NS ns1.stableserver.net.
supercp.com. 3 NS ns2.stableserver.net.
supercp.com. 3 NS ns4.stableserver.net.
Authority
The response has no authority records.
Additional
ns1.stableserver.net. 3 A 13.248.158.180
ns2.stableserver.net. 3 A 75.2.118.134
ns3.stableserver.net. 3 A 76.223.26.245
ns4.stableserver.net. 3 A 99.83.147.209
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0