From what I could gather, the Iridium Browser doesn't let websites save Cookies and the likes, correct? (To secure personal data ig)
This game uses cookies to save the progress (because it tracks the Dead Ends via global variables)... So maybe that could be the reason why the access was denied. At least that would be my guess :')
Sadly I don't have an in-game console installed (actually i don't think my engine comes with one);; If you want to try sth, you could try the game in another browser of your liking and see if it works there?