If you opened a setup link on desktop, try scanning the QR or NFC with your iPhone camera to launch the App Clip.
Expected paths look like https://halo.screenzen.co/s/b or https://halo.screenzen.co/s/q/<DEVICE_ID>.
https://halo.screenzen.co/s/b
https://halo.screenzen.co/s/q/<DEVICE_ID>