Accessing your Feed File is a paid upgrade. If you haven't added this to your account, do so here to get started exporting it out into other channels.
After signing up, the File Feeds tab will be available in your main account interface. By default the following files can be exported:
Click the Generate files button found at the top right of the page to prompt the app to produce all three files.
Files are updated every 24 hours, however you can also click Generate files again to perform a manual update.
Note: This may take a couple of minutes to complete, depending on the size of your feed. It's best to click out of this page and back in shortly after to see if your file has been completed.