Did you take a look at the 3D Viewer Sample App?
In the Documentation for the module you can start the app as well (login credentials provided). There you see an example of how to use an already uploaded file that can be used.
Selecting a value from a list fetches the required data via a Nanoflow (Nanoflow_openCloud) and displays the example (here it is retrieved from the cloud)
In your case, you could upload the file in your app and refer to that file in the logic in the nanoflow retrieve.
It is not a 100% straight forward answer, but hope it points you in the right direction.
Note: If you create an app locally, you can use the Add Snapshot feature (Version Control menu) to make a copy of your database. This database will be used for every new instance of the app (eg another developer loading the app for the first time).