Apex domains cannot have CNAME records.
Question and response
Question
dig fiord.RU. NS
Answer
fiord.ru. 5 NS ns1.fiord.ru.
fiord.ru. 5 NS cloud-ns2.fiord.ru.
fiord.ru. 5 NS ns3.fiord.ru.
Authority
The response has no authority records.
Additional
ns1.fiord.ru. 5 A 62.140.230.9
ns3.fiord.ru. 5 A 62.140.239.1
cloud-ns2.fiord.ru. 5 A 91.247.185.231
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0