If a video’s link is not shared by its uploader, an extension cannot “find” or “see” it. Extensions marketed this way are either:
Potential Features of a Responsible Extension see unlisted videos youtube extension
Google will often index unlisted video pages. If the video title appears in the search results but not on the YouTube channel page, you have likely found an unlisted video. If a video’s link is not shared by
Finding unlisted YouTube videos through extensions or tools typically relies on identifying videos that have been shared publicly elsewhere, as unlisted videos do not appear in standard YouTube search results or on channel pages. Extensions & Tools Finding unlisted YouTube videos through extensions or tools
To be clear, there is that allows you to "crack" or search all unlisted videos on demand . By design, unlisted videos require a direct link to be viewed.
Filmot (Search Engine/Extension)