I'm having mostly failures downloading, seems sequences are stored on Onedrive and most fail to download.
For the single one I got to download, it was a .piz file. Which was the way-around uploading zip files to Facebook groups a few years ago. Maybe it's scraping off other sites?
It's obviously scraping off other sites and doesn't bother to remember where and be kind enough to tell you that. It would also appear to be a "vibe coded" site... done by AI to "optimize for plausibility" but end up largely to be BS. See that this is obviously a John Storms sequence... but sure, let's let someone "claim" it? And the text above that ... AI nonsense. There are reasons people are throwing shade at AI (for scraping, coding, or both), and a few are evident here.