You can upload multiple images, videos and PDFs to a story at the same time. Just go to the story editor and follow these steps:
1. Click the + button located on the right of the story editor:
2. A pop-up window will appear showing the files on your computer. Navigate to the files you wish to upload and click on one of them.
3. Hold down the 'Ctrl' key (on a PC) or the 'Command' key (on a Mac) and select another file you wish to upload. Both will show as being selected. You can continue doing this until you have finished selecting all the files you wish to upload.
4. Click Open. All the selected files will begin uploading to your story.
If you have selected a lot of files, they may take a while to upload (this will also depend on your internet speed), but you can continue writing the story while you wait.