You are developing several microservices to run on Azure Container Apps for a company. External TCP ingress traffic from the internet has been enabled for the microservices. The company requires that

The `metadata` field is a collection of key-value pairs that provides the specific configuration details for the chosen KEDA scaler, such as `connectionStringSetting`, `consumerGroup`, and `eventHubName` for an Azure Event Hub trigger.

The `type` field specifies the event source for the KEDA scaler (e.g., 'azure-eventhub'), which tells KEDA which specific scaler to use to monitor and react to events.

The `authenticationRef` field is used to refer to an external `TriggerAuthentication` object for authentication, but it is optional and not as fundamental as `type` and `metadata` for defining the core scaling logic.

The `name` field is an optional identifier for the trigger and does not affect its functionality for scaling based on the event source.

The `metricType` field is typically associated with Horizontal Pod Autoscaler (HPA) metrics or specific KEDA scalers for interpreting metric values, but it's not a general top-level field for defining the event source itself in KEDA triggers.