Apex domains cannot have CNAME records.
Question and response
Question
dig twcc.ai. NS
Answer
twcc.ai. 4 NS ns2.twcc.ai.
twcc.ai. 4 NS ns1.twcc.ai.
Authority
The response has no authority records.
Additional
ns1.twcc.ai. 4 A 203.145.219.81
ns2.twcc.ai. 4 A 203.145.219.113
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0