Resolved Issues with IronSource SDK

I'm migrating from Unity Mediation to LevelPlay and i cannot make it work

I'm following this guide https://developers.is.com/ironsource-mobile/unity/unity-plugin/#step-1

✅ I removed the Unity Mediation package
✅ I downloaded and installed LevelPlay package
✅ I setup all the ad networks
✅ Added this to android manifest <uses-permission android:name="com.google.android.gms.permission.AD_ID"/>
✅ Added this to mainTemplate.gradle android.enableDexingArtifactTransform=false
✅ Resolved Android dependencies
✅ Looked at the sample project code, and implemented the code to my game
❌ Tested on the editor, SdkInitializationCompletedEvent() never gets triggered (not sure if its normal behavior)
❌ Testing on device i get the following errors:

Code (CSharp):

1. setUnityInitializationListener method doesn't exist, error: java.lang.NoClassDefFoundError: Failed resolution of: Lcom/ironsource/mediationsdk/sdk/InitializationListener;
2. setUnityRewardedVideoListener method doesn't exist, error: java.lang.NoClassDefFoundError: Failed resolution of: Lcom/ironsource/mediationsdk/sdk/InitializationListener;
3. ... And so on ...

What am I doing wrong?

Edit code I used

Code (CSharp):

1.   void Start()
2.     {
3.        InitStartAds();
4.     }
5.  
6.  
7.     void OnApplicationPause(bool isPaused)
8.     {
9.        IronSource.Agent.onApplicationPause(isPaused);
10.     }
11.     void InitStartAds()
12.     {
13.  
14.  
15.         Debug.Log("Initializing Ads...");
16.         Status = "Initializing Ads....";
17.         StatusUI.text = Status;
18.         IronSource.Agent.init("mygameid");
19.         IronSourceEvents.onSdkInitializationCompletedEvent += SdkInitializationCompletedEvent;
20.  
21.  
22.     }
23.     private void SdkInitializationCompletedEvent()
24.     {
25.         Debug.Log("Ads Initialized!");
26.         Status = "Ads Initialized!";
27.         StatusUI.text = Status;
28.         Ads_St = true;
29.  
30.     }

 

I fixed the issue, by deleting the LevelPlay Plugin which by the way I found it here where it says Download Unity Plugin Version 7.4.0
And installing the Ads Mediation found in the Package Manager. (I also had to restart Unity)
Then I did a build and initialization worked.