Any AUD amount you send to your unique Auto Buy deposit details will be used, once processed, to immediately and automatically Express Buy bitcoin.
You can also set up recurring payments from your bank account to said details. This is an easy way to DCA (Dollar Cost Averaging, also known as Recurring Buy).
To find your Auto Buy deposit details, please go to 'Account --> Deposit' and toggle 'Auto Buy' to ON or go to 'Buy --> Auto Buy'.