I do believe that you need software to create an image that you download. I was not aware until your question how to do it with my software. I use Buzzxplore and found out you can do it with that. What software are you using for your file system? So before I found out how to do it with my software, I made an item with the design and scanned the image of the sewn design. But you can do with a few clicks of your mouse with software. If you have BuzzXplore I can tell you how on that software.

Does the design have a name? Many sites use their initials in the design name that is a start if you don't have software to capture the image. If you do have software it depends on the kind you have how to save an image. Once it is saved check tutorials on the left and look for how to upload a picture tutorial.