Apex domains cannot have CNAME records.
Question and response
Question
dig tarifasweb.com. NS
Answer
tarifasweb.com. 5 NS ns2.tarifasweb.com.
tarifasweb.com. 5 NS ns1.tarifasweb.com.
Authority
The response has no authority records.
Additional
ns1.tarifasweb.com. 5 A 82.223.82.161
ns2.tarifasweb.com. 5 A 82.165.3.188
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0