I’ve only found TV rips of the series while sailing. Is there a way to download the videos?
They download the file (which you can usually do with a little Inspect Element
action + yt-dlp), but then also decrypt the file.
Most of the big streaming services use Widevine DRM (or at least did at one point, I might be outdated by now), so just downloading the file gives you appropriately-sized gibberish. These apps tend to be expensive because getting around the DRM is usually non-trivial.