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