Format Adjustment for VBA-WEB dictionary to JSON Body

I asked a question before, but I didn't ask it well... so after I did some more homework I realised I need help with the conversion of VBA dictionary into a specific JSON format to be sent as the Body of an API POST query.

Here is what I have:

Dim Body As New Dictionary

Body.Add "applicationId", "customsHub"
Body.Add "exportAsContentType", "NOT_ZIPPED_SINGLE"
Body.Add "documents", New Dictionary

With Body("documents")
    .Add "documentIds", New Dictionary
    
    With Body("documents")("documentIds")
    .Add "documentId", "491e2229-471a-4b18-907a-0e25a312e5a7"
    End With
    
End With

Output:

{
  "applicationId": "customsHub",
  "exportAsContentType": "NOT_ZIPPED_SINGLE",
  "documents": {
    "documentIds": {
      "documentId": "491e2229-471a-4b18-907a-0e25a312e5a7"
    }
  }

What I need to get -

{
  "applicationId": "customsHub",
  "exportAsContentType": "NOT_ZIPPED_SINGLE",
  "documents": 
  {
    "documentIds": 
    [
      {
        "documentId": "491e2229-471a-4b18-907a-0e25a312e5a7"
      }
    ]
  }
}

How do I add this nested array as part of the VBA dictionary pre-conversion?

"[]" characters in Json means an array. So you should create the last New Dictionary inside an array:

Sub createDict_REturnJson()
  Dim Body As New scripting.Dictionary

  Body.Add "applicationId", "customsHub"
  Body.Add "exportAsContentType", "NOT_ZIPPED_SINGLE"
  Body.Add "documents", New scripting.Dictionary

  With Body("documents")
    .Add "documentIds", Array(New scripting.Dictionary) 'place the dictionary in an array
    
    With Body("documents")("documentIds")(0) 'place the item as the array first element:
    .Add "documentId", "491e2229-471a-4b18-907a-0e25a312e5a7"
    End With
    
  End With

  Dim Json As String ' to test the output:
  Json = JsonConverter.ConvertToJson(Body, 2) 'supposing that you use JsonConverter module...
  Debug.Print Json
End Sub

To better catch the idea you can replace this part:

  With Body("documents")
    .Add "documentIds", Array(New scripting.Dictionary) 'place the dictionary in an array
    
    With Body("documents")("documentIds")(0) 'place the item as the array first element:
      .Add "documentId", "491e2229-471a-4b18-907a-0e25a312e5a7"
    End With    
  End With

with the next one, adding two dictionaries in the array, the first one keeping two keys (IDs) and the second one only one (only for didactic purpose...):

  With Body("documents")
    .Add "documentIds", Array(New scripting.Dictionary, New scripting.Dictionary) 'placing two dictionaries in the array
    
    With Body("documents")("documentIds")(0)
        .Add "documentId", "491e2229-471a-4b18-907a-0e25a312e5a7" 'first dictionary first key
        .Add "documentId2", "testID2" 'first dictionary second key
    End With
    Body("documents")("documentIds")(1).Add "DocumentID3", "TestID3" 'second dictionary first (single) key...
  End With