When I make the following API call I get results from the default IT Helpdesk instance:

GET https://{ORG_SERVICEDESK_URL}/api/v3/requests/

I get a list of requests from the default instance, "IT Helpdesk". I would like to be able to make the same call to a different instance, "DepartmentA" but can't figure out how to pass that through in my call.

Does anyone know how to call requests from a non-default instance?