Azure - Debugging Iot Hub - Function trigger

I'm trying to get the payload of Azure IoT Hub telemetry to a Function. I tried using this documentation, but I must be missing something. While I see data coming through, my function is not executed. I tried to put a Service Bus in between, so I created a Message Route in my IoT Hub and used that according to the same documentation, but for Service Bus instead of IoT Hub. I see the messages from a simulated device in the IoT Hub and the Service Bus, but somehow, the function is not executed. I also have no idea how to debug this problem, why the function is not executed. Any help with debugging tips or documentation tips would be much appreciated.

I added the Service Bus parameters in host.json:

...
        "serviceBus": {
            "prefetchCount": 100,
            "messageHandlerOptions": {
                "autoComplete": true,
                "maxConcurrentCalls": 32,
                "maxAutoRenewDuration": "00:05:00"
            },
            "sessionHandlerOptions": {
                "autoComplete": false,
                "messageWaitTimeout": "00:00:30",
                "maxAutoRenewDuration": "00:55:00",
                "maxConcurrentSessions": 16
            },
            "batchOptions": {
                "maxMessageCount": 1000,
                "operationTimeout": "00:01:00",
                "autoComplete": true
            }
        }
...

And set the right trigger binding in functions.json:

{
  "scriptFile": "__init__.py",
  "bindings": [
    {
      "name": "msg",
      "type": "serviceBusTrigger",
      "direction": "in",
      "queueName": "[MyQueueName]",
      "connection": "Endpoint=sb://[MyServiceBusName].servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=[MyServiceBusSAS]"
    }
  ]
}

Solution

So what the instructions lack to tell you, what I did wrong, is that you should give your connection an arbitrary name, say queue_conn_str. Then on the Azure Portal, you go to your function app, and set there the application setting with the actual connection string (Endpoint...), with the same name (queue_conn_str). With that you can actually connect your IoT hub directly to your function, no need for an Event Hub or Service Bus in between.