Fix cellular update failing

It won't activate cellular? If not that, what do you mean by won't update?

iPhone – Won’t activate. https://support.apple.com/en-us/HT201407

iPhone/iPad - No Service or Searching. https://support.apple.com/en-us/HT201415

If you see an Update Failed or Apple Pay Not Available alert after iOS update or restart - Apple Support

I need fix phone call

how to fix cellular phone call

how to fix cellular phone call

Click on the blue letters in my post just above yours. It is a link.