Apex domains cannot have CNAME records.
Question and response
Question
dig onlinenic.com. NS
Answer
onlinenic.com. 5 NS ns-1555.awsdns-02.co.uk.
onlinenic.com. 5 NS ns-232.awsdns-29.com.
onlinenic.com. 5 NS ns-861.awsdns-43.net.
onlinenic.com. 5 NS ns-1525.awsdns-62.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0