Apex domains cannot have CNAME records.
Question and response
Question
dig vm1.fi. NS
Answer
vm1.fi. 5 NS ns1.vm1.fi.
vm1.fi. 5 NS ns2.vm1.fi.
vm1.fi. 5 NS ns3.vm1.fi.
Authority
The response has no authority records.
Additional
ns1.vm1.fi. 5 A 135.181.156.58
ns2.vm1.fi. 5 A 116.203.33.198
ns3.vm1.fi. 5 A 95.111.205.213
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0