Hey there, @SueCabral!
Ryder here, from the Social Care Team at Shopify. Thanks for posting! Are you able to elaborate on what you mean by the Oberlo Advanced Pricing? Are you referring to the Oberlo Global Pricing Rules? Oberlo imports pricing in USD, so if you're selling in AUS you'll want to ensure that you set your store selling currency accordingly within the Shopify Admin. If you're wanting to use the Oberlo Global Pricing rules, you'll want to take the conversion rate into consideration when adjusting the settings. You can check out this guide for more information on how to do that.
If that doesn't appear to be the reason your Global Pricing rules are greyed out or if you're referring to something else by "Oberlo Advanced Pricing", would you be able to elaborate where it is you're seeing this? If you could also include a screenshot of what it is you're seeing exactly, that'll help me better understand what seems to be the issue and how I may be of assistance.