Apex domains cannot have CNAME records.
Question and response
Question
dig minicrm.io. NS
Answer
minicrm.io. 5 NS ns-362.awsdns-45.com.
minicrm.io. 5 NS ns-1621.awsdns-10.co.uk.
minicrm.io. 5 NS ns-1394.awsdns-46.org.
minicrm.io. 5 NS ns-928.awsdns-52.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0