Apex domains cannot have CNAME records.
Question and response
Question
dig vidriosjunioreu.com. NS
Answer
vidriosjunioreu.com. 5 NS ns2.vidriosjunioreu.com.
vidriosjunioreu.com. 5 NS ns1.vidriosjunioreu.com.
Authority
The response has no authority records.
Additional
ns1.vidriosjunioreu.com. 5 A 216.108.229.28
ns2.vidriosjunioreu.com. 5 A 216.108.229.91
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0