ABAP and SAP BI RESTful Web Services

I am trying to connect to the SAP BI platform RESTful Web Services using an ABAP program.

The ABAP program should:

- Connect to the BI Platform

- Generate Token to establish a connection

- Get the list of reports from the BI Platform

So far, I have been able to connect to the BI Platform but I was never able to generate the Token.

Using the ABAP REST library, I am trying to create the Token using the authenticate function but it is not working:

*user account data is specified via the AUTHENTICATE method
    g_http_client->authenticate(
      username = 'USERNAME'
      password = 'PASSWORD').

I know that the BI Platform RESTful services expect something like that:

<attrs xmlns="http://www.sap.com/rws/bip">
  <attr name="userName" type="string">USERNAME </attr>
  <attr name="password" type="string"> PASSWORD </attr>
  <attr name="auth" type="string" possibilities="secEnterprise,secLDAP,secWinAD,secSAPR3">secSAPR3 </attr>
  </attrs>

My question: How do I pass this to the BI Platform RESTful using ABAP? Should I do a POST function instead? Does anybody has an example on how I can connect using ABAP?

Thanks