Apex domains cannot have CNAME records.
Question and response
Question
dig cloudezapp.io. NS
Answer
cloudezapp.io. 5 NS ns4.cloudez.io.
cloudezapp.io. 5 NS ns5.cloudez.io.
cloudezapp.io. 5 NS ns3.cloudez.io.
cloudezapp.io. 5 NS ns2.cloudez.io.
cloudezapp.io. 5 NS ns1.cloudez.io.
Authority
The response has no authority records.
Additional
ns1.cloudez.io. 5 A 92.123.94.2
ns2.cloudez.io. 5 A 92.123.94.3
ns3.cloudez.io. 5 A 92.123.95.3
ns4.cloudez.io. 5 A 92.123.95.4
ns5.cloudez.io. 5 A 92.123.95.2
ns1.cloudez.io. 5 AAAA 2600:14c0:6:0:0:0:0:2
ns2.cloudez.io. 5 AAAA 2600:14c0:6:0:0:0:0:3
ns3.cloudez.io. 5 AAAA 2600:14c0:7:0:0:0:0:3
ns4.cloudez.io. 5 AAAA 2600:14c0:7:0:0:0:0:4
ns5.cloudez.io. 5 AAAA 2600:14c0:7:0:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0