IOS 13 update

In order to update wirelessly, suggestions are:

• Plug in your iPhone into power
• Connect it to a stable and possibly fast wifi network

If you can't complete your update wirelessly:--> Get help with over-the-air iOS updates - Apple Support

If you still can't update, try to perform the procedure via iTunes on a computer. If you don't have a computer, borrow one from your friends, or ask for hel at an Apple Store or AASP.

Regards

Giulio

You need to connect your iPhone to a wireless network or connect it directly to a Mac or PC, running iTunes. In turn that Mac or PC needs to be connected to the Internet. You cannot update over a cellular connection.