I strongly NOT recommend using an iPhone. PWA support is crap, and I don't even have a Mac or an iPhone to debug it.
I know about the blank screen issue: <https://cannon-chat.online/#three> It's not by design of course, it's because Apply actively refuses PWA as a viable technology on their platforms. Some people report Cannon won't show notification on Mac either. Use a desktop browser instead, it should work much better there.
