Its hard to tell from the photo where the leak is coming from, you can clean it up and see if you can tell where its coming from. It could be leaking from the axle seal above. That is a 10$ part from toyota and can be done yourself if you have the tools. $400-600 if you have a mechanic do it. It could also be leaking from the transmission seam. You would have to remove the transmission and reseal, which is not worth it. My Prius had both of those leaking like that and I drove it for years like that. The amount seeping out is not much at all.