A Unity ID allows you to buy and/or subscribe to Unity products and services, shop in the Asset Store and participate
in the Unity community.
It doesn't seem to be available for iOS ? This is the error I get when I try to build for iOS device....
Is it possible to Import a USDZ file? e.g, the guitar from here https://developer.apple.com/arkit/gallery/models/stratocaster/stratocaster.usdz
That worked thanks.
I'm having the same problem.