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