opt.walanja.com has no CNAME records.
Question and response
Question
dig opt.walanja.com. NS
Answer
The response has no answer records.
Authority
walanja.com. 3340 SOA ns1.cifo.co.id. admin.cmedia.co.id. 2020092807 7200 540 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0