How can I update the product quantity with the uploaded file count?

If you want to update the main product quantity to match the number of uploaded files, follow the steps below:

Enable setting

In the app, on your Upload field detail page, in the File settings section: 
Allowed number of files > Multiple files  > check "Update quantity to match count"

Enable quantity selector in theme

The app will look for the quantity selector on your theme to update with the current upload file count.

Make sure that you have the quantity selector enabled on your theme.  Depending on your theme the setting can be on different locations in the theme editor.

On the Dawn theme you can add a block "Quantity selector" on the product tempalte:

If you need further assistance, please send us a request and we will be happy to help you out.