Unable to activate
Why is my iPhone saying “An update is required to activate your iPhone”?
iPhone 8 Plus, iOS 14
Question marked as
See -> If you can't activate your iPhone or iPad (Wi-Fi + Cellular)
If you can't activate your iPhone or iPad (Wi-Fi + Cellular) - Apple Support
See these Apple articles below:
Manually update your carrier settings on your iPhone or iPad
Manually update your carrier settings on your iPhone or iPad - Apple Support
Update your network provider settings manually on your iPhone or iPad
Update your network provider settings manually on your iPhone or iPad – Apple Support (UK)