Yes. Use this article on how to upload preprocessed data to upload your existing datasets.
I still can't do it!
We wrote these articles to arm you with everything you need to get the job done on your own, but we understand that sometimes this isn't sufficient.
If you're stuck, the Propeller data success team may be able to help. You can contact our support team by clicking the support tab on the top-right pane of your user portal.