@ Suhar:
We will not know for sure whether a broker is NDD or DD unless we join or work at the broker so we know if the order is thrown or held. What we hold on to is the regulation. As long as the broker is regulated by a credible international regulatory body, namely: CFTC, NFA, FCA, FSA, FINMA, MiFID, ASIC and FMA, we don't need to worry about where our order goes.
A credible regulatory body is one that has been tested and internationally recognized, and provides strict sanctions to brokers if they violate agreed terms. The regulatory body is also responsible for the security of client funds.
Regarding OCTAFX, I asked customer support (customer support) representing OCTAFX Indonesia, here is the content of the chat:

So according to OCTAFX, the broker is an NDD type (can be STP or DMA), and there are also ECN accounts.
The regulation is as mentioned above. Previously regulated by FCA UK (the website mentions being regulated by FCA UK, but customer support says it is only for clients from the UK).
For more complete information, you can read at: Review And Broker Profile Octafx