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