Apex domains cannot have CNAME records.
Question and response
Question
dig piksel.eu. NS
Answer
piksel.eu. 5 NS ns.piksel.eu.
piksel.eu. 5 NS ns2.piksel.ee.
Authority
The response has no authority records.
Additional
ns.piksel.eu. 5 A 217.159.201.70
ns2.piksel.ee. 5 A 195.222.24.129
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0