Image files with the .jpg or .png extension can be registered to the clipboard. Drag and drop the image files from your device to the clipboard to register them.
Video files cannot be directly registered from your device. First, upload the video file to a step, and then register that step to the clipboard.
Related:
Register a video (Web browser version)
https://teachme.jp/8/manuals/4881166
Use clipboard function (Web Browser)
https://teachme.jp/8/manuals/11054649