Issue in getting PDF of the completed document.

I have created a template. I create and send the document from this template using this

API https://sign.zoho.com/api/v1/templates/[Template Id]/createdocument .

The API response has document id which I save in a database.

Sample response in API documentation:

"document_ids": [
      {
        "image_string": "<BASE 64 Image String>",
        "document_name": "Employee NDA.pdf",
        "pages": [
          {
            "image_string": "<BASE 64 Image String>",
            "page": 0,
            "is_thumbnail": true
          }
        ],
        "document_size": 26591,
        "document_order": "0",
        "total_pages": 2,
        "document_id": "2000000492171"
      }

I need to get the PDF document after the signing of the document completed.

I tried to get the document details using the API with the saved document id.

https://sign.zoho.com/api/v1/requests/[Request Id]

https://sign.zoho.com/api/v1/requests/[Request ID]/pdf

It shows the error :

{"code":4003,"message":"Access to view the document is denied","status":"failure"}

I also see no documents with the that document id in Sent menu in the application. Looks like the signed document has different document id.

How do I fix this?