Apex domains cannot have CNAME records.
Question and response
Question
dig hidroelectrica.gov.do. NS
Answer
hidroelectrica.gov.do. 1 NS ns1.egehid.gob.do.
hidroelectrica.gov.do. 1 NS ns2.egehid.gob.do.
Authority
The response has no authority records.
Additional
ns1.egehid.gob.do. 1 A 190.167.197.234
ns2.egehid.gob.do. 1 A 190.167.197.235
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0