Apex domains cannot have CNAME records.
Question and response
Question
dig tl.teralab-datascience.fr. NS
Answer
tl.teralab-datascience.fr. 5 NS ns1.tl.teralab-datascience.fr.
tl.teralab-datascience.fr. 5 NS ns2.tl.teralab-datascience.fr.
Authority
The response has no authority records.
Additional
ns1.tl.teralab-datascience.fr. 5 A 212.129.40.207
ns2.tl.teralab-datascience.fr. 5 A 195.90.118.211
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0