For a non-proxy integration, you must set up at least one integration response, and make it the default response, to pass the result returned from the backend to the client. You can choose to pass through the result as-is or to transform the integration response data to the method response data if the two have different formats. For a proxy integration, API Gateway automatically passes the backend output to the client as an HTTP response. You do not set either an integration response or a method response.
integration vs method response