There is not a way to update your iOS device using mobile data. You’ll have to use your wifi. If you don’t have wifi at your place, maybe use a friend’s, or go to a wifi hotspot, like a library. You can also update it through iTunes on your Mac or PC if you have an internet connection there.

Can I update my iPhone using cellular data?

You can update ios 13 using cellphone data

As you need internet connectivity to update your iOS 12/13, you can use your cellular data in place of WiFi. You need to check that you have enough data plan in your mobile as the updating requires a lot more data.

Can you update iOS without WiFi?

No. Not unless you have a computer running iTunes that has an Internet connection. … You need an Internet connection to update iOS. The time it takes to download the update varies according to the size of the update and your Internet speed.