Apex domains cannot have CNAME records.
Question and response
Question
dig careersitecloud.com. NS
Answer
careersitecloud.com. 5 NS ns-1690.awsdns-19.co.uk.
careersitecloud.com. 5 NS ns-1211.awsdns-23.org.
careersitecloud.com. 5 NS ns-194.awsdns-24.com.
careersitecloud.com. 5 NS ns-872.awsdns-45.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0