Tree can’t support its own weight send help

Hey all, just moved into a new place in Melbourne and I have some type of flower tree in the backyard that can’t support its own weight. Been having strong winds the past few months which has been pushing the tree until it ended up like this.

It just constantly falls over and I don’t know what I can do about this. I’ve got a piece of wood holding it up but just after a permanent solution. Soil is also very soft and it hasn’t been raining recently.

Thank you all!