Apex domains cannot have CNAME records.
Question and response
Question
dig optincomplaint.com. NS
Answer
optincomplaint.com. 5 NS ns1.optincomplaint.com.
optincomplaint.com. 5 NS ns2.optincomplaint.com.
Authority
The response has no authority records.
Additional
ns1.optincomplaint.com. 5 A 163.5.51.249
ns2.optincomplaint.com. 5 A 85.17.54.203
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0