Apex domains cannot have CNAME records.
Question and response
Question
dig tggo.com.hk. NS
Answer
tggo.com.hk. 4 NS ns01.hdcdatacentre.com.
tggo.com.hk. 4 NS ns02.hdcdatacentre.com.
Authority
The response has no authority records.
Additional
ns01.hdcdatacentre.com. 4 A 202.123.77.209
ns02.hdcdatacentre.com. 4 A 202.123.77.213
ns01.hdcdatacentre.com. 4 AAAA 2407:7200:2000:0:0:0:0:209
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0