Apex domains cannot have CNAME records.
Question and response
Question
dig redreturns.net. NS
Answer
redreturns.net. 4 NS meg.ns.cloudflare.com.
redreturns.net. 4 NS yevgen.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0