Apex domains cannot have CNAME records.
Question and response
Question
dig senkodns.net. NS
Answer
senkodns.net. 5 NS ns2.senkodns.net.
senkodns.net. 5 NS ns1.senkodns.net.
Authority
The response has no authority records.
Additional
ns1.senkodns.net. 5 A 193.23.211.20
ns2.senkodns.net. 5 A 144.31.19.180
ns1.senkodns.net. 5 AAAA 2a12:bec4:1bb0:ff1:0:0:0:1001
ns2.senkodns.net. 5 AAAA 2a12:bec4:1b50:291:0:0:0:2002
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0