Hi Vapecouk ,
ATUM Export Pro can only be used from its menu entries. You can read here all the ATUM Export Pro available documentation.
If you want to export all your products' stock, you can use the included default template 'Products + ATUM Data' or you can create a template with only the data you need.
Please use the filtering options from the export screen to filter by a product's category. You can read here how the filters can be added.
Best Regards,
José Andrés