Trying to update to ios 13 and I am getting an error code 4003? Anyone seen this

Errors in the range of 4000-4016 have to do with issues involving the USB connection or security software.

For more information, click on the link provided below:

Resolve specific iTunes update and restore errors

Check USB connections

If there’s an issue with the USB port, cable, dock, or hub, or if the device becomes disconnected during restore, try troubleshooting the USB connection, then troubleshooting your security software.

To narrow down the issue, you can also change up your hardware:

• Use another USB cable.
• Plug your cable into a different USB port on your computer.
• Try a different dock connector (or no dock).
• Add (or remove) a USB hub between your device and computer.
• Connect your computer directly to your Internet source, with no routers, hubs, or switches.

If you see your error after changing your USB connections, continue to the next section to troubleshoot your hardware.

Perhaps this article will help:

iOS update and restore errors - Apple Support

If you see error 9, 4005, 4013, or 4014 when you restore your iOS device - Apple Support