Apex domains cannot have CNAME records.
Question and response
Question
dig lebroch.com. NS
Answer
lebroch.com. 5 NS ns-1235.awsdns-26.org.
lebroch.com. 5 NS ns-494.awsdns-61.com.
lebroch.com. 5 NS ns-928.awsdns-52.net.
lebroch.com. 5 NS ns-1594.awsdns-07.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0