Apex domains cannot have CNAME records.
Question and response
Question
dig hardenedstructuresofcalifornia.com. NS
Answer
hardenedstructuresofcalifornia.com. 5 NS ns-951.awsdns-54.net.
hardenedstructuresofcalifornia.com. 5 NS ns-599.awsdns-10.net.
hardenedstructuresofcalifornia.com. 5 NS ns-385.awsdns-48.com.
hardenedstructuresofcalifornia.com. 5 NS ns-738.awsdns-28.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0