Event Grid Blob Webhook for Azure Functions

Question

What part of the Azure functions services handles requests to the https://<FUNCTION_APP_NAME>.[azurewebsites.net/runtime/webhooks/blobs?functionName=Host.Functions.<FUNCTION_NAME>&code=]<BLOB_EXTENSION_KEY> endpoint referenced in this MS Learn Article?  Is it part of the Azure Functions Runtime docker image or is there some other package required to handle the post from Event Grid?

I have my own functions runtime running in Azure Kubernetes Service. The queue triggers work, the timer trigger works, and even the simple blob trigger at low volumes, but when I attempt to setup the Event Grid based blob trigger, I get 404s.

# curl -o - -I 'http://localhost/runtime/webhooks/blobs?functionName=Host.Functions.process_log_file&code=xxx'
HTTP/1.1 404 Not Found
Date: Fri, 21 Feb 2025 13:50:14 GMT
Server: Kestrel
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