Apex domains cannot have CNAME records.
Question and response
Question
dig eu-north-1.compute.amazonaws.com. NS
Answer
eu-north-1.compute.amazonaws.com. 5 NS ns-355.awsdns-44.com.
eu-north-1.compute.amazonaws.com. 5 NS ns-879.awsdns-45.net.
eu-north-1.compute.amazonaws.com. 5 NS ns-1123.awsdns-12.org.
eu-north-1.compute.amazonaws.com. 5 NS ns-1804.awsdns-33.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0