Apex domains cannot have CNAME records.
Question and response
Question
dig eu-central-1.elasticbeanstalk.com. NS
Answer
eu-central-1.elasticbeanstalk.com. 4 NS ns-470.awsdns-58.com.
eu-central-1.elasticbeanstalk.com. 4 NS ns-1701.awsdns-20.co.uk.
eu-central-1.elasticbeanstalk.com. 4 NS ns-1047.awsdns-02.org.
eu-central-1.elasticbeanstalk.com. 4 NS ns-833.awsdns-40.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0