Apex domains cannot have CNAME records.
Question and response
Question
dig dmarc-report.com. NS
Answer
dmarc-report.com. 5 NS ns-1488.awsdns-58.org.
dmarc-report.com. 5 NS ns-618.awsdns-13.net.
dmarc-report.com. 5 NS ns-248.awsdns-31.com.
dmarc-report.com. 5 NS ns-1801.awsdns-33.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0