dkim.brevo.com has no CNAME records.
Question and response
Question
dig dkim.brevo.com. NS
Answer
The response has no answer records.
Authority
dkim.brevo.com. 5 SOA ns1.sendinblue.com. hostmaster.brevo.com. 0 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0