Since the device says " call 911," are you in the US? Or the UK? The device selection is a bit different.
There are a couple of different ways to do this, including wiring something in line, but I will leave it to others to discuss that.
If you’re in the US, the Leeo acoustic sensor would be the simplest way to solve the use case.
This is a plug-in device which simply listens for specific acoustic patterns and then send you a push notification. It also has its own IFTTT channel, which can be used to integrate with SmartThings.
It can recognize The US mandated residential smoke alarm pattern, CO alarm pattern, and the continuous tone used by most water leak sensors. I don’t know if your sprinkler alarm will fit one of those patterns, but if it does, but Leeo is a fast and easy way to get integration. I use this at my own house for some older smoke alarms which are not otherwise that worked.
List price for the Leeo is $49, but it quite often goes on sale for $29 if you want to wait for a sale.
There are certainly other alternatives which involve wiring something in line if for whatever reason the Leeo does not appeal to you. But if you do want to give it a try, it’s a simple as plugging it in and setting up the app and you’re good to go.