If a third-party service requires specific response to its API-calls, you can easily do it using the API-response step. You can edit response for:
Return body. Actual response. Can contain data from object fields via the template system. You can compose JSON, XML or simple text here;
Return code. 200 – by default;
Content-type: JSON, XML or text.
Example. an external service would send an API-request to Directual via Webhook, and would expect a response in XML format
You should enter to "Return body" field the following: