Apex domains cannot have CNAME records.
Question and response
Question
dig hotseminarseries.com. NS
Answer
hotseminarseries.com. 5 NS ns-1206.awsdns-22.org.
hotseminarseries.com. 5 NS ns-510.awsdns-63.com.
hotseminarseries.com. 5 NS ns-487.awsdns-60.com.
hotseminarseries.com. 5 NS ns-871.awsdns-44.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0