Enabling Cognitive Search in Microsoft Chat Copilot / Semantic Kernel

Question

I'm new to Semantic Kernel & Chat Copilot and trying to integrate an existing Cognitive Search instance. Ideally I'd like to use a Custom Question Answering index as a first step. At first, I thought all I needed to do was configure:

 "AzureCognitiveSearch": {
        "Auth": "ApiKey",
        "APIKey": "[My Api Key]
        "Endpoint": "https://[myresource].search.windows.net"
      },

But that got me nowhere, so I tried also:

"Retrieval": {
     "VectorDbType": "AzureCognitiveSearch",
...
   },

But still nothing. From what I was able to find, that seemed to be all I needed to do? This is per https://github.com/microsoft/chat-copilot#optional-run-the-memory-pipeline . If possible, I'd really appreciate some guidance, but I'm also happy to assist with submitting a documentation PR based on that.