FedEx API documentation states: Note: FedEx customers can request both One Rate and weight based (non-One Rate) rates in a single Rate Request by specifying "FEDEX_ONE_RATE" as a Service Option Type in the request.
https://developer.fedex.com/api/en-us/catalog/rate/v1/docs.html
Where to specify this "Service Option Type" as "FEDEX_ONE_RATE" is never stated, though. There's a variableOptions property which seemed promising, though as a string or an array with string (the documentation is incorrect about the types of some properties) I get an error about an incorrect value.
{"transactionId":"5cdab900-959b-4a4a-b5dd-75fd27ad8c86","errors":[{"code":"INVALID.INPUT.EXCEPTION","message":"Invalid field value in the enum variableOptions"}]}
Currently I only see "one rate" rates and no "weight based" rates when I use the specialShipmentServices property. Does anyone have any experience with this? Is the documentation just wrong?