Importing STEP files with Insert mold parts

I am creating a design that will be injection molded and has some insert mold for threads.
I downloaded insert mold step files and added them to my project. The step file is added as a collection of Meshes in a folder (not a body). And when I export the parts, the meshes are ignored and only my modeled 3d object is exported and the insert molds are not exported. Is there a way for me to be able to export the imported STEP files too?