Be warned that you need to install an external windows app to download videos. But that's just the begining: after downloading the video, the extension/app need to "process" it. Why? To put a big QR code watermark into the video *sic*. To do that, your CPU will burn like it was mining crypto. So this extension it's a complete nonsense to me. My advise is to stay away from Video DownloadHelper and use something like youtube-dl instead.