If you mean you want create an empty excel with the right format to add stories in the excel and upload it when it's complete…
Then I suggest to 1st create a dummy story. Then Export it via the “More” button at the right hand side. See the picture and scroll to the right side.
Next page you can select what you want to export.
Next page you get the download button.
Clicking that button downloads the file.
Hope this helps.