Apex domains cannot have CNAME records.
Question and response
Question
dig freshworksapi.com. NS
Answer
freshworksapi.com. 5 NS ns-936.awsdns-53.net.
freshworksapi.com. 5 NS ns-1492.awsdns-58.org.
freshworksapi.com. 5 NS ns-1556.awsdns-02.co.uk.
freshworksapi.com. 5 NS ns-223.awsdns-27.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0