Apex domains cannot have CNAME records.
Question and response
Question
dig cse-online.net. NS
Answer
cse-online.net. 5 NS verify-contact-details.namecheap.com.
cse-online.net. 5 NS failed-whois-verification.namecheap.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0