Why isn't the knowledge article dmo not appearing in the select source object page ofr the Agentblazer legend "Create a search index configuration" module?

Create a Data Stream using the below steps and it will create the DMOs 

1. If you haven’t already, launch your Data Cloud custom playground.
2. Click the App Launcher, enter dataCopy and click the Data Cloud app.
3. In Data Cloud, go to the Data Streams tab, and click New.
4. Select the Salesforce CRM data source, and click Next.
5. Leave the default Salesforce org selected. Select the Knowledge data bundle, and click Next.
6. Review the fields that are included in your data stream–the default selection is perfectly fine for this challenge—and click Next.
7. Review the new data streams and objects to be deployed from the data stream kit, and click Deploy.