Apex domains cannot have CNAME records.
Question and response
Question
dig debt-advice-online.com. NS
Answer
debt-advice-online.com. 5 NS ns1.debt-advice-online.com.
debt-advice-online.com. 5 NS ns2.debt-advice-online.com.
Authority
The response has no authority records.
Additional
ns1.debt-advice-online.com. 5 A 184.105.221.89
ns2.debt-advice-online.com. 5 A 70.32.0.73
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0