Apex domains cannot have CNAME records.
Question and response
Question
dig zgctwh.org. NS
Answer
zgctwh.org. 5 NS ns-1559.awsdns-02.co.uk.
zgctwh.org. 5 NS ns-650.awsdns-17.net.
zgctwh.org. 5 NS ns-636.awsdns-15.net.
zgctwh.org. 5 NS ns-1061.awsdns-04.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0