You can use mobile data to download the latest version of iOS.

Before you begin: Make sure that you have a good cellular data connection and enough megabytes in your plan.

Follow these steps:

  1. Create a Hotspot from your iPhone. This helps to use the cellular data from your iPhone to connect to the web on your computer.
  2. Open iTunes and plug in your iPhone after that.
  3. In iTunes, click on the icon that represents your iPhone.
  4. Click on Check for Updates.
  5. Find the option to download and install iOS 13.

Your Mac/Windows will proceed to download iOS 13 using the Hotspot you created from your iPhone. iTunes will then install iOS 13 on your iPhone.

All the best with a fresh version of your iOS :)