Apex domains cannot have CNAME records.
Question and response
Question
dig cruail.com. NS
Answer
cruail.com. 5 NS ns-1363.awsdns-42.org.
cruail.com. 5 NS ns-587.awsdns-09.net.
cruail.com. 5 NS ns-766.awsdns-31.net.
cruail.com. 5 NS ns-1050.awsdns-03.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0