Apex domains cannot have CNAME records.
Question and response
Question
dig kiubi.com. NS
Answer
kiubi.com. 5 NS ns2.amen.fr.
kiubi.com. 5 NS ns1.amen.fr.
Authority
The response has no authority records.
Additional
ns1.amen.fr. 5 A 81.88.61.4
ns2.amen.fr. 5 A 81.88.63.39
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0