Apex domains cannot have CNAME records.
Question and response
Question
dig ugmk-telecom.ru. NS
Answer
ugmk-telecom.ru. 5 NS ns1.ugmk-telecom.ru.
ugmk-telecom.ru. 5 NS ns2.ugmk-telecom.ru.
Authority
The response has no authority records.
Additional
ns1.ugmk-telecom.ru. 5 A 89.251.66.7
ns2.ugmk-telecom.ru. 5 A 89.251.79.5
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0