Cellular data
My cellular data has an error message. My phone says “No Service” and it is searching. I can’t make calls, sometimes I get email and WhatsApp.
iPhone 7 Plus, iOS 15
See these Apple articles below:
If you see No Service or Searching on your iPhone or iPad
If you see No Service or Searching on your iPhone or iPad - Apple Support
If you can't make or receive calls on your iPhone
If you can't make or receive calls on your iPhone - Apple Support