Apex domains cannot have CNAME records.
Question and response
Question
dig smartape.RU. NS
Answer
smartape.RU. 5 NS ns4.smartape.RU.
smartape.RU. 5 NS ns3.smartape.RU.
Authority
The response has no authority records.
Additional
ns3.smartape.RU. 5 A 188.127.239.203
ns4.smartape.RU. 5 A 188.127.239.204
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0