Apex domains cannot have CNAME records.
Question and response
Question
dig structuredweb.com. NS
Answer
structuredweb.com. 3 NS ns-2006.awsdns-58.co.uk.
structuredweb.com. 3 NS ns-559.awsdns-05.net.
structuredweb.com. 3 NS ns-460.awsdns-57.com.
structuredweb.com. 3 NS ns-1032.awsdns-01.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0