You've put (what I presume should have been) the start of "no service" in your subject field, but left your post itself blank. I presume you meant to put a query along the lines of "I have no service, what should I do?". In which case...
If you've not done so already, try toggling flight mode to ensure your phone hasn't "dropped off" available coverage.
Use the "check service status" option on https://ee.co.uk/help/mobile-coverage-checker in the first instance, to check for local service outages. The "report a problem" link should be used if no issues are reported but EE users continue to have issues.A loss of coverage will remove the ability to make/receive calls, send/receive texts or use mobile data.
If you're in the UK and have a WiFi connection, you can use WiFi-calling to keep using your phone as normal without needing network coverage.
