Apex domains cannot have CNAME records.
Question and response
Question
dig pressreleasebase.com. NS
Answer
pressreleasebase.com. 5 NS ns-799.awsdns-35.net.
pressreleasebase.com. 5 NS ns-473.awsdns-59.com.
pressreleasebase.com. 5 NS ns-795.awsdns-35.net.
pressreleasebase.com. 5 NS ns-1359.awsdns-41.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0