Apex domains cannot have CNAME records.
Question and response
Question
dig migadu.com. NS
Answer
migadu.com. 5 NS ns2.migadu.com.
migadu.com. 5 NS ns0.migadu.com.
migadu.com. 5 NS ns1.migadu.com.
Authority
The response has no authority records.
Additional
ns0.migadu.com. 5 A 142.4.215.212
ns1.migadu.com. 5 A 37.187.73.171
ns2.migadu.com. 5 A 37.187.109.108
ns0.migadu.com. 5 AAAA 2607:5300:60:14d4:0:0:0:1
ns1.migadu.com. 5 AAAA 2001:41d0:a:29ab:0:0:0:1
ns2.migadu.com. 5 AAAA 2001:41d0:a:626c:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0