Apex domains cannot have CNAME records.
Question and response
Question
dig rotkva.com. NS
Answer
rotkva.com. 1 NS ns-207.awsdns-25.com.
rotkva.com. 1 NS ns-1708.awsdns-21.co.uk.
rotkva.com. 1 NS ns-1575.awsdns-04.co.uk.
rotkva.com. 1 NS ns-1745.awsdns-26.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0