Apex domains cannot have CNAME records.
Question and response
Question
dig egain.cloud. NS
Answer
egain.cloud. 3 NS ns-1969.awsdns-54.co.uk.
egain.cloud. 3 NS ns-647.awsdns-16.net.
egain.cloud. 3 NS ns-423.awsdns-52.com.
egain.cloud. 3 NS ns-1484.awsdns-57.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0