Order API problem for using Private App on mobile devices by Evan Huang

Hi,

I'm building an iOS app for my own Shopify store. I created a private app and using the API key and password to call APIs with the format https://apikey:password@hostname/admin/resource.json.

Problem occurs when I try to use the API to make payment status change for orders.  (I can make a new order without problem). I don't find any API for changing financial status for an order. I cannot change the financial status by modifying an order or I even cannot may any transactions by API no matter the "kind" of transactions is "authorisation", "capture" or "sale". 

So how can I change the financial status of an order using the API on the device?

Here is an example for the request and response of using the API:

API:

/admin/orders/#{order_id}/transactions.json

request:

{
    "transaction":
        {
            "amount": 50, 
"test":true,
            "kind": "sale"
        }

}

response:

{"errors":{"kind":["sale is not a valid transaction"]}}