Apex domains cannot have CNAME records.
Question and response
Question
dig scdingtai.com. NS
Answer
scdingtai.com. 4 NS ns2.scdingtai.com.
scdingtai.com. 4 NS ns1.scdingtai.com.
Authority
The response has no authority records.
Additional
ns1.scdingtai.com. 4 A 104.206.86.155
ns2.scdingtai.com. 4 A 51.161.109.21
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0