Initialize the SDK in Unity

To initialize the SDK, you must reference your project's Game ID for the appropriate platform. You can locate the Game ID from the Unity Ads Monetization dashboard by selecting the Monetization suite, navigating to your current project, then Settings in the secondary navigation bar, and scrolling to the Game IDs section.

In your game script header, include the UnityEngine.Advertisements namespace. Initialize the SDK early in the game's run-time life cycle, preferably at launch, using the Initialize function. In SDK versions 3.7.0 and later, you can use IUnityAdsInitializationListener callbacks to receive a notification when initialization is complete, or receive the details when an error occurs.

using UnityEngine;
using UnityEngine.Advertisements;
 
public class AdsInitializer : MonoBehaviour, IUnityAdsInitializationListener
{
  [SerializeField] string _androidGameId;
  [SerializeField] string _iOSGameId;
  [SerializeField] bool _testMode = true;
  private string _gameId;
 
  void Awake()
  {
    InitializeAds();
  }
 
  public void InitializeAds()
  {
    #if UNITY_IOS
    _gameId = _iOSGameId;
    #elif UNITY_ANDROID
    _gameId = _androidGameId;
    #elif UNITY_EDITOR
    _gameId = _androidGameId; //Only for testing the functionality in the Editor
    #endif
 
    if (!Advertisement.isInitialized && Advertisement.isSupported)
     {
       Advertisement.Initialize(_gameId, _testMode, this);
     }
  }

  public void OnInitializationComplete()
  {
    Debug.Log("Unity Ads initialization complete.");
  }
 
  public void OnInitializationFailed(UnityAdsInitializationError error, string message)
  {
    Debug.Log($"Unity Ads Initialization Failed: {error.ToString()} - {message}");
  }
}

Next steps: To continue your integration, refer to the Implement interstitial ads in Unity documentation.