Apex domains cannot have CNAME records.
Question and response
Question
dig tmsoftware.is. NS
Answer
tmsoftware.is. 5 NS ns01.t.is.
tmsoftware.is. 5 NS ns02.t.is.
Authority
The response has no authority records.
Additional
ns01.t.is. 5 A 217.28.178.10
ns02.t.is. 5 A 217.28.177.20
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0