To download the version, you first install the free extension and then purchase a license key to unlock the "Premium" features. While the base extension is free on the Chrome Web Store and Firefox Add-ons , the Premium upgrade removes watermarks from converted videos and enables features like HLS downloading and direct conversion to MP3. How to Get Premium
The free version limits HLS (streaming) downloads to one every 120 minutes. Premium removes this restriction. Video Conversion: Video Downloadhelper Premium Download