Apex domains cannot have CNAME records.
Question and response
Question
dig layer3.ng. NS
Answer
layer3.ng. 5 NS kimora.ns.cloudflare.com.
layer3.ng. 5 NS alaric.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0