Chartboost integration in Unity

Hi, i want to integrate Chartboost into My Android Unity 3D Game.
I am a begginer so i don’t know exactly what i must do.
I downloaded the Chartboost SDK and Imported in Unity, i changed my app ID and signature ID in Unity and now ?
I want to display ads on the landscape screen from time to time.
How can i do this, can you help me, please ?

Ok i added Chartboost prefab with Chartboost Script but it doesn’t work. No interstitial ad showing.

You have to create a Campaign on Charboost Website and set test mode to enabled

and change the settings in Unity

more I dont know