Apex domains cannot have CNAME records.
Question and response
Question
dig HOSTPRO.RU. NS
Answer
HOSTPRO.RU. 5 NS savanna.ns.cloudflare.com.
HOSTPRO.RU. 5 NS major.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0