Virtual base for Ortho Model

We are trying to create a virtual base for ortho models. They are supposed to be printed afterwards. The problem right now is to connect the virtual base with the stl file of the scan.
I know that Shapr3D is supposed to be used by engineers and designers but we need a solution for this that can be used on iPad.
I’ll add a picture of what it should look like. I’m thankful for any help. Thanks guys!

On the left side is what we want to have and on the right a picture of the scan

Hi, thanks for reaching out. Referencing the attached images, I will suggest you recreate the model in the app using the scanned data as an outline. This will also then enable you to model and attach the virtual base.

We have a great webinar on reverse engineering a scanned data to a 3d model and you could get some insights from it: