If your Excel spreadsheet file isn't showing in the folder, first try searching for it by typing its name in the Search field.
If after your file still isn't listed, this may be because you've saved it in a different file format. Geckoboard only supports the
.xlsx file extension for Excel files. As a result, any
.xlsm files won't be listed in your folder.
You'll need to save your workbook again as an
.xlsx file type. If you're unsure on how to this, follow this guide to saving a workbook in another file format.