Apex domains cannot have CNAME records.
Question and response
Question
dig 18allbet.com. NS
Answer
18allbet.com. 5 NS ns-943.awsdns-53.net.
18allbet.com. 5 NS ns-868.awsdns-44.net.
18allbet.com. 5 NS ns-291.awsdns-36.com.
18allbet.com. 5 NS ns-985.awsdns-59.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0