Apex domains cannot have CNAME records.
Question and response
Question
dig oraclerealm17.com. NS
Answer
oraclerealm17.com. 3 NS ns5.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com.
oraclerealm17.com. 3 NS ns1.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com.
oraclerealm17.com. 3 NS ns7.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com.
oraclerealm17.com. 3 NS ns3.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com.
oraclerealm17.com. 3 NS ns2.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com.
oraclerealm17.com. 3 NS ns4.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com.
oraclerealm17.com. 3 NS ns6.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com.
Authority
The response has no authority records.
Additional
ns1.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com. 3 A 151.104.196.172
ns2.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com. 3 A 151.104.196.11
ns3.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com. 3 A 151.104.197.12
ns4.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com. 3 A 151.104.205.214
ns5.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com. 3 A 151.104.205.31
ns6.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com. 3 A 151.104.213.54
ns7.p200.dns.us-dcc-phoenix-1.oci.oraclerealm17.com. 3 A 151.104.212.111
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0