Apex domains cannot have CNAME records.
Question and response
Question
dig oksimel19.net. NS
Answer
oksimel19.net. 5 NS ns.oksimel19.net.
oksimel19.net. 5 NS sdns2.ovh.net.
Authority
The response has no authority records.
Additional
ns.oksimel19.net. 5 A 87.98.180.28
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0