How to use the "Publish a datasource" RestAPI to load an external data source to tableau? How do I load my file with the request body? The instructions on RestAPI reference did not seem clear enough.

I have been trying to use the "Publish a data-source" rest api given in the Tableau RestAPI reference to use a file from Zuora and publish to Tableau as a datasource however, I couldn't understand how exactly do I upload the file using that API. Please help me understand the process.

Find the current request body and header attached below (Do not know how to upload file for data-source).

Header:

X-Tableau-Auth : the_token_obtained_from_sign_in

Content-Type : multipart/mixed; boundary=6691a87289ac461bab2c945741f136e6

Request Body:

--6691a87289ac461bab2c945741f136e6

Content-Disposition: name="request_payload"

Content-Type: text/xml

<tsRequest>

  <workbook name="workbook_name">

    <project id="project_id"/>

  </workbook>

</tsRequest>

--6691a87289ac461bab2c945741f136e6

Content-Disposition: name="tableau_workbook"; filename="usps-rates.twbx"

Content-Type: application/octet-stream

<content here>//How do I use the content??

--6691a87289ac461bab2c945741f136e6--

Response:

<?xml version='1.0' encoding='UTF-8'?>

<tsResponse xmlns="http://tableau.com/api" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://tableau.com/api http://tableau.com/api/ts-api-3.4.xsd">

    <error code="500000">

        <summary>Forbidden</summary>

        <detail>User does not have permission for action.(The server encountered an error and cannot complete your request. Contact your server administrator.)</detail>

    </error>

</tsResponse>