Applications for WSU's HSC True Reward Early Offer Program are made through the westernsydney.uac.edu.au portal (similar to other universities such as MQ and UTS) as opposed to the standard uac.edu.au portal, the latter being used mainly for standard ATAR-based applications. It works in a slightly different way to schemes such as SRS, which would require you to have your chosen course listed as your highest eligible UAC preference by a specified date (this implies the need to make a standard application through UAC, which you may already be aware of). This means that if you receive a True Reward offer based on your year 11 results, you are essentially good to go.
Keep in mind that you will still need to complete your HSC if you are applying on the basis of year 11 results.
I hope this helps!