If you recently downloaded it, check your Reddit "History" or "Saved" tabs in your profile.
If you can take a screenshot of a clear frame from the video, use Google Lens or TinEye to find the original thread. 0h8axkjfx83onf4nz4skv_source.mp4
Since the filename is an internal server ID, there isn't a public "directory" to look it up. However, you can try these steps to find the original post: If you recently downloaded it, check your Reddit