Apex domains cannot have CNAME records.
Question and response
Question
dig sudu-y94k.com. NS
Answer
sudu-y94k.com. 5 NS ns12.bigwww.com.
sudu-y94k.com. 5 NS ns11.bigwww.com.
Authority
The response has no authority records.
Additional
ns11.bigwww.com. 5 A 39.96.153.43
ns11.bigwww.com. 5 A 47.118.199.203
ns12.bigwww.com. 5 A 47.118.199.203
ns12.bigwww.com. 5 A 120.76.107.43
ns11.bigwww.com. 5 AAAA 2408:4009:501:0:0:0:0:9
ns12.bigwww.com. 5 AAAA 2408:4009:501:0:0:0:0:10
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0