# Initialize SDK

### Use the Manager in Unity Scripts

Integrate Playtime Ads SDK into your app by following these simple steps. Ensure proper initialization, offer wall access, and optional SDK cleanup for best results.

Now you can use `PlaytimeAdsManager.Instance` to call SDK functions anywhere in your Unity project:

## Initialize the SDK with User ID 

Use your **Application Key** and a unique **User ID** from your system to initialize the SDK.

```csharp
// Initialize with user ID
PlaytimeAdsManager.Instance.InitializeWithUserId(<YOUR_APPLICATION_KEY>,<USER_ID>);
```

{% hint style="warning" %}
Replace `"<YOUR_APPLICATION_KEY>"` and `“<USER_ID>”` with your actual app key provided by Playtime SDK and logged-in user id.
{% endhint %}