Apex domains cannot have CNAME records.
Question and response
Question
dig toppkopie.com. NS
Answer
toppkopie.com. 5 NS ns-138.awsdns-17.com.
toppkopie.com. 5 NS ns-1169.awsdns-18.org.
toppkopie.com. 5 NS ns-493.awsdns-61.com.
toppkopie.com. 5 NS ns-1334.awsdns-38.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0