the website only works in chrome or firefox. Apparently they didn’t bother to make it compatible with safari. I had no issue setting a passkey once I used any browser other than safari. Kind of ironic since apple was one of first adopters and pushers of passkeys yet blizzard would completely ignore testing it on safari (but that’s part for the course with their level of mac support)
That said, i don’t think bnet will use pw until a later update (or beta). I haven’t tested if it works or not on macOS though (and I doubt blizzard has either)