Apex domains cannot have CNAME records.
Question and response
Question
dig sigep.gob.bo. NS
Answer
sigep.gob.bo. 5 NS ns3.sigep.gob.bo.
sigep.gob.bo. 5 NS ns2.sigep.gob.bo.
sigep.gob.bo. 5 NS ns1.sigep.gob.bo.
Authority
The response has no authority records.
Additional
ns1.sigep.gob.bo. 5 A 190.181.50.199
ns2.sigep.gob.bo. 5 A 190.14.104.8
ns3.sigep.gob.bo. 5 A 186.121.222.8
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0