Apex domains cannot have CNAME records.
Question and response
Question
dig zynovetra.com. NS
Answer
zynovetra.com. 5 NS ns-1967.awsdns-53.co.uk.
zynovetra.com. 5 NS ns-721.awsdns-26.net.
zynovetra.com. 5 NS ns-75.awsdns-09.com.
zynovetra.com. 5 NS ns-648.awsdns-17.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0