Apex domains cannot have CNAME records.
Question and response
Question
dig diser.hn. NS
Answer
diser.hn. 5 NS ns01.diser.hn.
diser.hn. 5 NS ns02.diser.hn.
Authority
The response has no authority records.
Additional
ns01.diser.hn. 5 A 164.163.72.2
ns02.diser.hn. 5 A 164.163.73.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0