Yes you can. In normal times, cancelling a Oneworld booking attracts a fee of 6,000 points per passenger; but that is currently waived. From the website:
...whether you’re looking to travel soon or down the track, when you use points to book a Classic Flight Reward, you’ll be able to change your travel dates or cancel your booking free of charge.*
Simply book:
an Australian domestic Classic Flight Reward before 30 April 2022 and you can change or cancel your booking free of charge until 30 April 2022
an Trans-Tasman or International Classic Flight Reward before 30 June 2022 and you can change or cancel free of charge until 31 December 2022
If you wish to change your travel dates, we’ll waive the change fee. If you wish to cancel, we’ll waive the cancellation fee. The total Qantas Points used and any taxes, fees and carrier charges paid will be refunded.