What files can I upload and whats the size limit?

For the downloadable file: any and all file types are supported.

Size limit: 3gb

For the preview images: any image file, mp4, or .GLB

Size limit: 3gb

MP4s and GLB (3D files)

If you want to have a 3D image that can be interacted it by anyone - you just need to upload a .GLB file as one of the preview images.

MP4s are also accepted as a means to play videos if the user wants to watch it.

You still need to upload a basic image as the display image if you choose either of these types.