problem w iPhone 11pro

Is the phone in Airplane mode? Does it have a SIM card?

Is this the problem you are seeing—>If you see No Service or Searching on your iPhone or iPad - Apple Support or does it show a carrier name, and just doesn’t work?

Is it a new problem, or has it never worked?

Have you tried restarting the phone—>Restart your iPhone - Apple Support?

Have you checked with your carrier for a local outage, or checked on this crowd-sourced site—>Down Detector - outages

With just a statement, we couldn't possibly know what the issue is with your phone.

Here is a link which may help you determine what the issue is --> If you can't make or receive calls on your iPhone - Apple Support