Convert STEP to EPRT

eDrawings are similar to PDFs and can only produced in SolidWorks. Which means for step to eprt conversion to work (export of ISO STEP product data files), you have to import these and process in SolidWorks before you can export them to EPRT format. It is unlikely any other software can help you with this, so if you have other issues with export to eDrawing, you have to contact SolidWorks support or some community forum for help.