How to find an iPhone device UDID

1. Connect your iPhone to your Mac.
2. If you're asked to trust the device, tap Trust to grant it permission.
3. Open the Finder app.
4. In the Location section in the Finder sidebar, click the device to display its information.
5. This will display the device page with details and options for the device.
6. Click the details immediately below the device name to toggle different details about the device until you see the UDID.