I’m not sure how bambu studio does it (use prusa/superslicer) but chiming in because I was trying to figure this out last year doing a large ish batch of keychains for a friend and was fighting a bit with it, probably is a way of doing it all in freecad but the image was my biggest issue.

I ended up doing things in blender to subtract the image and the slicer itself, did a text object, positioned it where I wanted, merged the objects and marked the text as a negative volume so it was subtracted when I sliced it, might help in your case?