how to upload the download file

Make sure you have the Download Monitor plugin installed. When logged in to WordPress as administrator, look for the “Downloads” link on the left-side menu. That is Download Monitor. Once you are in there you can add/upload a file and you can look at a list of your uploaded files and then edit one if you want (which takes you to the detail screen with options and the file title and such). Download Monitor is a little weird in how it’s edit screen kind of works — you may need to refer to their docs if you get confused.