Apex domains cannot have CNAME records.
Question and response
Question
dig netledger.com. NS
Answer
netledger.com. 3 NS ns3.p202.dns.oraclecloud.net.
netledger.com. 3 NS ns1.p202.dns.oraclecloud.net.
netledger.com. 3 NS ns2.p202.dns.oraclecloud.net.
netledger.com. 3 NS ns4.p202.dns.oraclecloud.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0