Apex domains cannot have CNAME records.
Question and response
Question
dig prolan.pf. NS
Answer
prolan.pf. 5 NS ns2.vini.pf.
prolan.pf. 5 NS ns1.vini.pf.
Authority
The response has no authority records.
Additional
ns1.vini.pf. 5 A 202.90.66.43
ns2.vini.pf. 5 A 202.90.66.51
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0