Apex domains cannot have CNAME records.
Question and response
Question
dig ispguatemala.com.gt. NS
Answer
ispguatemala.com.gt. 5 NS ns2.ispguatemala.com.gt.
Authority
The response has no authority records.
Additional
ns2.ispguatemala.com.gt. 5 A 190.121.192.234
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0