# Missing application ID

Discover the solution for application ID not detected.

The following error occurs when the Application ID is not specified in either the `<script>` tag or the [`plug`](/reference/sdk/javascript/api/plug/plug) method call.

> **Error**
>
> The app ID must be specified when it cannot be auto-detected. Please try again specifying the `appId` option.

To resolve this issue, specify the [`appId`](/reference/sdk/javascript/api/plug/plug) option when [initializing the SDK](/reference/sdk/javascript/integration#initialize). You can find the Application ID on the [Integration page](https://app.croct.com/redirect/organizations/-organization-/workspaces/-workspace-/applications/-application-/integration) of your application.