Apex domains cannot have CNAME records.
Question and response
Question
dig mx3.timeweb.RU. NS
Answer
mx3.timeweb.RU. 5 NS ns1.timeweb.RU.
mx3.timeweb.RU. 5 NS ns4.timeweb.org.
mx3.timeweb.RU. 5 NS ns3.timeweb.org.
mx3.timeweb.RU. 5 NS ns2.timeweb.RU.
Authority
The response has no authority records.
Additional
ns1.TIMEWEB.RU. 3 A 85.193.93.93
ns2.timeweb.ru. 3 A 85.193.93.85
ns3.timeweb.org. 3 A 217.78.234.130
ns4.timeweb.org. 3 A 139.45.249.139
ns1.TIMEWEB.RU. 3 AAAA 2a03:6f04:dead:bee:0:0:0:1
ns2.timeweb.ru. 3 AAAA 2a03:6f04:dead:bee:0:0:0:2
ns3.timeweb.org. 3 AAAA 2a03:6f07:4:0:0:0:0:2
ns4.timeweb.org. 3 AAAA 2a00:65e0:6:5:232a:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0