Where I can use Tizen Power Request..?

according this: Power: Controlling Power Resources

  tizen.power.request("SCREEN", "SCREEN_NORMAL");

Where in my code I should use this…? What I need to do is to get my display always on when I´am on app.

On your initial function. On the one that always runs when you open the app.
For instance, if your application is a web app you could add that code on the “onload” event…

OK to maybe there is a problem, that this feature is not available on my app…?

 using Tizen.Security;
 using Tizen.Sensor;
 using Tizen.Location;
 using Tizen.System;

 namespace Pulsometer

 public partial class App : Application
    public App()
        Tizen.Power.Request("SCREEN", "SCREEN_NORMAL");
        MainPage = new Pulsometer.MainPage();

There is error: The type or namespace name ‘Power’ does not exist in the namespace ‘Tizen’ (are you missing an assembly reference?)

using Tizen.System.Power or Tizen.Power is not available…?