Apex domains cannot have CNAME records.
Question and response
Question
dig doctorconn.com. NS
Answer
doctorconn.com. 4 NS ns-991.awsdns-59.net.
doctorconn.com. 4 NS ns-422.awsdns-52.com.
doctorconn.com. 4 NS ns-118.awsdns-14.com.
doctorconn.com. 4 NS ns-403.awsdns-50.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0