How to detect if device has gone to sleep/wake/lock/unlock [MacCatalyst]

[fireking220]

I have some Dispatch Timers in my app that get paused when the computer goes to sleep/lock on Mac. I would like to be able to detect wake/sleep/lock/unlock for mac so that I can restart these timers with the time remaining. For example

Expected:

1. Launch app
2. Timer gets set for 5 minutes
3. Sleep/Lock for 1 minute
4. Computer wakes/unlocks
5. Timer gets updated to end after 4 minutes

Actual:

1. Launch app
2. Timer gets set for 5 minutes
3. Sleep/Lock for 1 minute
4. Computer wakes/unlocks
5. Timer is still set to go off after 5 minutes

I have tried this, but cant seem to get the callbacks set up correctly to the notifications

public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
    NSNotificationCenter.DefaultCenter.AddObserver(new NSString("NSWorkspaceWillSleepNotification"), notify: 
    n => 
    {
        Console.WriteLine("Sleep!");
    });
}

Is there any way to do this, or is it currently impossible because of MacCatalyst?