Apex domains cannot have CNAME records.
Question and response
Question
dig pggmb.org.bn. NS
Answer
pggmb.org.bn. 5 NS ns2.duxhub.com.
pggmb.org.bn. 5 NS ns3.duxhub.com.
pggmb.org.bn. 5 NS ns4.duxhub.com.
pggmb.org.bn. 5 NS ns1.duxhub.com.
Authority
The response has no authority records.
Additional
ns1.duxhub.com. 5 A 13.248.158.180
ns2.duxhub.com. 5 A 75.2.118.134
ns3.duxhub.com. 5 A 76.223.26.245
ns4.duxhub.com. 5 A 99.83.147.209
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0