Apex domains cannot have CNAME records.
Question and response
Question
dig kbrw.fr. NS
Answer
kbrw.fr. 5 NS dns01.kbrw.fr.
kbrw.fr. 5 NS dns03.kbrw.fr.
Authority
The response has no authority records.
Additional
dns01.kbrw.fr. 5 A 176.31.90.163
dns03.kbrw.fr. 5 A 51.210.69.196
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0