The cellular data couldn't update on my phone. So, I backed my phone up through iTunes and tried to Restore it. It seemed to restore but then as I went to set it up, it said "Unable to Activate an Update is Required to Update your iPhone"
iPhone XS, iOS 12
Hi! Check this: If you can't activate your iPhone - Apple Support
I've done all that. I did a restore through iTunes and that's what the screen said.
When the phone was still semi-working, I tried to do this but was unable. Now, the restore through iTunes has also failed
Few Carrier (Cellular Service Provider) do not provide Carrier Settings in full but they offer APN settings for example
Settings > Mobile Data > APN [under Mobile Data APN] enter the APN pin
Use the APN pin based on your carrier. Ask them or google and search.
If you do see the option to enter APN then the only option is give below
Carrier Update (Required): Released by your Cellular Service provider (Carrier Update), affects your Outgoing / Incoming calls, SMS, Data etc..
How to Update Carrier Settings
You can manually check for and install a carrier settings update with these steps: Make sure your device is connected to a Wi-Fi or cellular network. Tap Settings > General > About. If an update is available, you'll see an option to update your carrier settings.
Update your carrier settings on your iPhone or iPad - Apple Support
Unable to activate an update is required to activate your iphone
