Apex domains cannot have CNAME records.
Question and response
Question
dig nutrarewards.com. NS
Answer
nutrarewards.com. 5 NS ns-929.awsdns-52.net.
nutrarewards.com. 5 NS ns-1882.awsdns-43.co.uk.
nutrarewards.com. 5 NS ns-1767.awsdns-28.co.uk.
nutrarewards.com. 5 NS ns-2001.awsdns-58.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0