Singapore: do stockbrokers have to send all orders to SGX?

Suppose I have an account at a stock brokerage firm in Singapore. If place an order to buy or sell one lot of shares, will my order be sent to the stock exchange (SGX) and get executed there? Is it compulsory for stockbrokers to route all customer orders to the stock exchange, or are stockbrokers allowed to internalize the orders instead?

I have skimmed the SGX-ST Rules — Chapter 5 Trading Practices and Conduct (in particular 5.4 Acting as Principal to Customer and 5.5 Acting as Agent to Customer), but the situation is still unclear to me.