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