Apex domains cannot have CNAME records.
Question and response
Question
dig srv02.aloojamiento.com. NS
Answer
srv02.aloojamiento.com. 5 NS ns4.aloojamiento.com.
srv02.aloojamiento.com. 5 NS ns3.aloojamiento.com.
Authority
The response has no authority records.
Additional
ns3.aloojamiento.com. 5 A 38.58.229.3
ns4.aloojamiento.com. 5 A 38.65.227.221
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0