In Toolpath:
Stock mode: Accessible in Overview
Automatic - offsets model geometry based on your Stock Preset
From Body - allows selection of geometry in the uploaded file
Fixed Box - allows designation for XYZ dimensions
Fixed Cylinder - allows designation of diameter and length of a cylinder
From Fusion:
In Setup: Stock From Body
When choosing Mode: From Solid and selecting your Stock Body in a Fusion setup you can send that setup directly to Toolpath. Toolpath will also program within the setup orientations you provide.
Ensure stock is set to "From Preceding Setup" for subsequent setups.
Multiple Bodies in a .step file:
If you export a .step file with multiple bodies shown in your Fusion feature tree, when this part gets uploaded to Toolpath, the body will be selectable in under From Body in Stock Mode.
Select From Body - which will allow selection of stock geometry in the uploaded file