If you have auto-backup enabled, the video may be stored in the cloud under the date October 9, 2019 .

Do not click on random "Download" links from unknown websites claiming to host this specific file. Since it is a private WhatsApp filename, any public download link is likely spam or malware .

Use a file explorer app to search your entire storage for VID 20191009 WA0000 .

Sometimes media that won't load on your phone is still viewable if you log in via a computer.

Are you trying to a deleted video, or did you find this link in a specific tutorial you're following?