Apex domains cannot have CNAME records.
Question and response
Question
dig prowly.com. NS
Answer
prowly.com. 5 NS ns-19.awsdns-02.com.
prowly.com. 5 NS ns-1198.awsdns-21.org.
prowly.com. 5 NS ns-870.awsdns-44.net.
prowly.com. 5 NS ns-2042.awsdns-63.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0