Amazon's official stance is that downloads are intended for temporary offline viewing on a single device, such as a phone, tablet, or PC. Download location
Officially, for the purpose of playing them on other devices . While the Amazon Prime Video app allows you to save titles for offline viewing, these files are protected by Digital Rights Management (DRM) and can only be played within the official app on the specific device used for the download. The Official Policy and Its Limitations can you download movies from amazon prime to a flash drive