How to Approve a Purchase Order with REST API

Content

I have a situation that need to approval a purchase order using REST API.

I seach this API /bpm/api/4.0/tasks/ , but when executed display this message.

BODY

{

"action": { "id":"APPROVE"}

}

 

RESPONSE

{

    "hasMore": false,

    "items": [

        {

            "hasSubTasksFlag": false,

            "approvalDuration": 0,

            "title": "No Action specified",

            "length": 0

        }

    ]

}

 

Any suggestion ?

 

 

Version

21 C