STL convert/export? App

Hi I’m newbie enough…I’ve made a few things now with shpr3d and it’s been great…still plenty to learn I’m a jeweler, can anyone recommend an iPad app the will allow organic drawing exporting as stl to import into Shapr3D? An app that would convert a line drawing or image to an stl, currently im using AI on my desktop upload to box and download to Shapr3D. It works but it means I’m teathered to the desktop, maybe that’s just what it is? I also chose not to get AI for the tablet because apple doesn’t allow the plug-in I need so for now I’m on the desktop.

Any thoughts helpful