Create a downloadable product

To avoid download issues, use a filename that doesn't include special characters, such as “?”. Stick to alphanumeric characters.

Ensure you have a category with a “product delivery option” set to “downloaded by the customer”. While you can make your default category “downloaded by the customer”, this is not recommended unless you are only selling downloadables, as otherwise it can lead to unintended errors with non-downloadable products. You'll create your category in the FoxyCart product categories in your admin.

Click the “downloadables” link in your FoxyCart admin navigation, then click the “add a product” link. Alternatively, you can use this link to go to your product downloadables settings.

Select the appropriate file to upload, and the appropriate category, product name (as displayed to the customer), product code (unique per product, per category), and price.

Upload the file.

Create an add-to-cart link or form, making sure to include the necessary category and code. Note that without the appropriate category and code values, the addition of the product to the cart will either error, or will add a normal, non-downloadable product. Also worth noting is that with downloadable products you do not have to pass in the product's name to the cart, since that is set explicitly on the server-side.