Query parameters are a flexible way to modify the response of an API request. You can use them to filter, sort, and paginate results. They are added to the end of an endpoint URL, following a question mark (?), with multiple parameters separated by an ampersand (&).
Optional. If set to true, the response will include an object containing the response payload. This is useful for debugging and for retrieving the full resource details without a subsequent GET call. It’s generally used on create/update requests (e.g., POST /v3/payment) to control whether the response includes a full object.
Default is false
E.g. By adding ?echo=true to your payment creation request, the API response will contain both the result of the transaction and the data you originally sent.
