Is there a possibility to wake a monitor from sleep, when a website content changes?

I'm a firefighter and I'm trying to set up an alert monitor in our fire department which summarizes the alert information.

This monitor should be in standby until a website on the connected Windows 10 PC displays a different alert message. Then it should wake up for a specified amount of time.

I've tried to do this using task-scheduler but didn't get the result I hoped for.