Apex domains cannot have CNAME records.
Question and response
Question
dig interactivedns.com. NS
Answer
interactivedns.com. 5 NS secondary.interactivedns.com.
interactivedns.com. 5 NS primary.interactivedns.com.
Authority
The response has no authority records.
Additional
primary.interactivedns.com. 5 A 139.59.76.2
secondary.interactivedns.com. 5 A 172.105.60.6
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0