AppFlow Event Triggers for custom connectors

Hi,

The AppFlow documentation in several places mentions the ability to trigger a flow based on an event (e.g. "Run the data flows at the frequency you choose, whether on a schedule, in response to a business event, or on demand" https://aws.amazon.com/appflow/) but I can't find many details about these event triggers. Is the SalesForce connector the only one that supports this?

Is it possible to create a custom connector with an event trigger, e.g. a webhook? Having looked at the python and java sdk examples these don't appear to show how to implement an event trigger (https://github.com/awslabs/aws-appflow-custom-connector-java, https://github.com/awslabs/aws-appflow-custom-connector-python).