If you recently downloaded it, check your Reddit "History" or "Saved" tabs in your profile.
Paste 0h8axkjfx83onf4nz4skv into the Reddit search bar or Google. If the post was popular, it may appear in search results or archives.
If you can take a screenshot of a clear frame from the video, use Google Lens or TinEye to find the original thread.
The filename is a unique identifier typically generated by Reddit's video hosting service (v.redd.it) .