You're on a computer. Cell Service - Verification System is built for phones - open on your phone to install it there. On a desktop you can still explore the app in demo mode.
While a test is running,keep the app on screen. Installing it to your home screen makes that easier, but phones still pause background pages, so a locked screen pauses the test.
App developed & provided for Trent Hills and Northumberland County by Steven Haylestrom.