You could use a Surefoot footing for a steel pier - there are members here who have done that. Here are the candidate footings:
https://surefootfootings.com.au/pile-cap-s400/
https://surefootfootings.com.au/pile-cap-s500/
They're relatively quick to install and moveable if you move house, so might work for renters as well.
One member here posted a Youtube video of a temporary pier setup in the bush using one of these just to show how quickly it could be done - I'll post the link if I can find it.