Cellular Update on Iphone 7
How can I do a cellular update on my phone?
iPhone 7, iOS 14
Go to Settings/General/About, and if there is a carrier update available you will be prompted to install it. If that isn’t what you mean (for example, if your phone shows No Service or Searching) see→If you see No Service or Searching on your iPhone or iPad - Apple Support.
Also, if you have an iPhone 7, see→If you see No Service or Searching on your iPhone or iPad - Apple Support