Apex domains cannot have CNAME records.
Question and response
Question
dig ANKH.fr.eu.org. NS
Answer
ANKH.fr.eu.org. 5 NS nsa.fdn.fr.
ANKH.fr.eu.org. 5 NS kell-vultr.ANKH.fr.eu.org.
ANKH.fr.eu.org. 5 NS gchq.fdn.fr.
Authority
The response has no authority records.
Additional
nsa.fdn.fr. 3 A 80.67.169.25
gchq.fdn.fr. 3 A 80.67.169.26
KELL-VULTR.ANKH.FR.EU.ORG. 5 A 108.61.198.35
nsa.fdn.fr. 3 AAAA 2001:910:800:0:0:0:0:25
gchq.fdn.fr. 3 AAAA 2001:910:800:0:0:0:0:26
KELL-VULTR.ANKH.FR.EU.ORG. 5 AAAA 2001:19f0:5001:5d:5400:ff:fe4c:714f
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0