Apex domains cannot have CNAME records.
Question and response
Question
dig supportbeemail.com. NS
Answer
supportbeemail.com. 2 NS eva.ns.cloudflare.com.
supportbeemail.com. 2 NS nile.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0