Apex domains cannot have CNAME records.
Question and response
Question
dig igarve.com. NS
Answer
igarve.com. 5 NS ns-1782.awsdns-30.co.uk.
igarve.com. 5 NS ns-1944.awsdns-51.co.uk.
igarve.com. 5 NS ns-23.awsdns-02.com.
igarve.com. 5 NS ns-714.awsdns-25.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0