Thanks Abhishek and Nils,
We get the x-csrf-token by sending not only the SAP username, password but also the NW Gateway SAP's username password. @Channel you should check hopefully it will work for you as well.
Now, once we send the data back (Cookie and Token). We get the following error.
The server is refusing to process the request:
<?xml version="1.0" encoding="utf-8"?><error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata"><code>SY/530</code><message xml:lang="en">Resource not found for the segment 'req_appr'.</message><innererror><transactionid>52FA1039154C315FE1000000C0A80217</transactionid><errordetails><errordetail><code>/IWBEP/CX_MGW_BUSI_EXCEPTION</code><message>Resource not found for the segment 'req_appr'.</message><propertyref/><severity>error</severity></errordetail></errordetails></innererror></error>
Please help.