Yes, it is possible to specify in the header or query parameters. In addition to the default JSON format, CSV and XML can also be specified as the output format. You can also specify the output of a JSON file that is compressed in ZIP format.
Some models do not support formats other than JSON, such as authentication.
Specifying in the header
Specify in the Accept header.
Specifying in the query parameters
If you want to change the data structure of the CSV output by rewriting the headers, etc., refer to How to Implement Original Function into the Postprocess.