A Windows PC cannot build an iPhone app
Apple only allows iPhone apps to be built and signed on macOS using Xcode, which Apple does not release for Windows. This is Apple's restriction, not a missing feature in kneecap — no emulator or virtual machine makes it work reliably.
What you can do instead
- Borrow a Mac for about half an hour — the signature it installs lasts 7 days and can be renewed on any Mac.
- Use an Android phone instead, which builds fine from Windows and has its own export pipeline.
- Edit on the desktop web build instead — no install, though it has no phone camera roll and no on-device export.
This is a limit of the phone and computer combination, not of kneecap. Every other combination has a full guide.