Apex domains cannot have CNAME records.
Question and response
Question
dig coolrocksmartpop.com. NS
Answer
coolrocksmartpop.com. 5 NS ns2.coolrocksmartpop.com.
coolrocksmartpop.com. 5 NS ns1.coolrocksmartpop.com.
Authority
The response has no authority records.
Additional
ns1.coolrocksmartpop.com. 5 A 104.168.101.66
ns2.coolrocksmartpop.com. 5 A 104.168.101.67
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0