Many "Fighting Kids DVDs" are out of print. You can legally buy second-hand physical discs on eBay for $5-$15. Then rip your own copy to your personal Google Drive for backup (fair use, not distribution).
Many public libraries still have DVDs on their shelves. Search your library's online catalog for: fighting kids dvd google drive
If you are trying to track down a specific title or type of content, let me know: Is it a or an instructional fitness program ? What decade or era is the media from? Many "Fighting Kids DVDs" are out of print