Apex domains cannot have CNAME records.
Question and response
Question
dig ebilling.com. NS
Answer
ebilling.com. 5 NS ns4.brcc.digital-delivery.com.
ebilling.com. 5 NS ns1.brcc.digital-delivery.com.
ebilling.com. 5 NS ns2.brcc.digital-delivery.com.
ebilling.com. 5 NS ns3.brcc.digital-delivery.com.
Authority
The response has no authority records.
Additional
ns1.brcc.digital-delivery.com. 4 AAAA 2600:9000:5307:fe00:0:0:0:1
ns2.brcc.digital-delivery.com. 4 AAAA 2600:9000:5304:3b00:0:0:0:1
ns3.brcc.digital-delivery.com. 4 AAAA 2600:9000:5301:c00:0:0:0:1
ns4.brcc.digital-delivery.com. 4 AAAA 2600:9000:5302:e400:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0