iPhone 7 no service
Why iphone 7 saying no service
Why iphone 7 saying no service
Contact your cellular carrier and see if there is some issue with their service.
If your carrier says everything is fine, your iPhone may have a known hardware issue. Apple can repair it for free even if out of warranty:
Details here:
iPhone 7 Repair Program for "No Service" Issues - Apple Support
iPhone 7 no service