Many ecommerce stores choose to offer downloadable products, from video and music files to software and instructions. With OpenCart, you can offer downloadable products to your customers straight away without needing any customisation or additional features on your store.
Before you can add a download to a product, you'll first need to upload the files to your OpenCart store. To do this, log into your admin area and navigate to Catalog > Downloads and click the blue plus (+) button to add a new download. When adding a download, you'll see three fields as shown in the screenshot below. The "Download Name" should be something that both yourself and your customer will recognise as it'll be shown in both the admin area and the customer's account. Use the "Upload" button to upload the desired file for the download, once you've selected the file the "Filename" and "Mask" fields will automatically populate based off the filename. For security reasons, you should always make sure that the "Mask" is different to the "Filename".
Now that your download has been added to your store, you can now add it to your desired product. Go to Catalog > Products and edit the product you wish to use, then go to the "Links" tab. Towards the bottom of this page there will be a field called "Downloads" - in this field, type the name of the download you wish to use and select it from the suggestions which will appear. Once selected, save the product using the save button at the top right of the screen. If this product is only a download and doesn't include a physical product, remember to change the "Requires Shipping" option to "No".
Your download will now be linked to your product and will appear in the customer's account once they've placed their order as shown below. As the customer has to get their download from their account, guest checkout can not be used with downloadable products.