Rest API integration object

I have no information regarding your external document management application.  Let's call it DMA for right now.

However, I expect it's possible that DMA returns its own unique identifier for the new document you just added.  You should be able to capture that from the response of the first call.
Is there a second Update Indexes API call for DMA that takes that unique identifier? 
If so, you should be able to pass in those indexes along with the new unique identifier in a second API call to DMA from Appian.

This application is called DocuWare. At this moment i have 2 itegration objects in my process. First is loging in and second is send document. I need to send this indexes with document im not sure I can edit them later. It look similar to my #1 attachment.

Upload object is at the #2 attachment

These indexes arent unique i think. You can have many documents for the same client, branch or from the same date

The thing to keep in mind is that Appian is entirely dependent on how the system works that you want to integrate with. There are a number of possibilities: add query parameters, add information in the request body, add parameters to the URL, etc. However, DocuWare is likely expecting to receive these indexes in a certain way. I'd suggest doing some research on DocuWare to see what format they need to store indexes, then craft your integration to meet those requirements.

I found this in Documantation but i have no idea why it doesnt work for me

{                  

      "Fields": [
           {
               "FieldName": "DWWBSOURCE",
               "Item": "xyz",
               "ItemElementName": "String"
                                         }
                 ]
}

Changed into
{
 "Fields": 
 {
 "FieldName": "ACCOUNTNUMBER",
 "Item": ri!metadata.AccountNumber,
 "ItemElementName": "String"
 }

I chose Multipart Form Data and enter this as JSON + document which has document content type

I don't think that's the correct syntax for using Multipart Form Data. Usually you have to either add the properties directly to the grid or use the a!httpFormPart() function to define the data to send. See here for more information.

I'd suggest starting by using the option for "Specify values for each part" and plug in the properties you defined above. If that doesn't work, try the expression that returns a list of a!httpFormPart()

Can't find "Specify values for each part" in 19.2. Was it implemented in 19.4?

Is there any alternative? Maybe custom  type?

Can't find "Specify values for each part" in 19.2. Was it implemented in 19.4?

Is there any alternative? Maybe custom  type?

I found some informations: I have to send this indexes as  PUT method in xml, but there is a problem now

<?xml version="1.0" encoding="utf-8"?><DocumentIndexFields xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://dev.docuware.com/schema/someservices"><Field FieldName="ACCOUNTNOUM"><String>A1</String></Field></DocumentIndexFields>

How can i put this into xml? I tried to create CDT with FieldName and String felds and then made something like this in request body

'type!{urn:com:appian:types}DW_DocumentIndexFields'(
FieldName: "ACCOUNTNUMBER",
String: "A1"
)

and  gives me an 500 error