public async void RequestLockScreenAccess()
    {
        var status = BackgroundExecutionManager.GetAccessStatus();
        if (status == BackgroundAccessStatus.Unspecified || status == BackgroundAccessStatus.Denied)
            status = await BackgroundExecutionManager.RequestAccessAsync();
        switch (status)
        {
            case BackgroundAccessStatus.AllowedWithAlwaysOnRealTimeConnectivity:
                _mainInfo.NotifyUser = "This app is on the lock screen and has access to Always-On Real Time Connectivity.";
                break;
            case BackgroundAccessStatus.AllowedMayUseActiveRealTimeConnectivity:
                _mainInfo.NotifyUser = "This app is on the lock screen and has access to Active Real Time Connectivity.";
                break;
            case BackgroundAccessStatus.Denied:
                _mainInfo.NotifyUser = "This app is not on the lock screen.";
                break;
            case BackgroundAccessStatus.Unspecified:
                _mainInfo.NotifyUser = "The user has not yet taken any action. This is the default setting and the app is not on the lock screen.";
                break;
        }
    }

status = await BackgroundExecutionManager.RequestAccessAsync();