api extension

RestApi extension in JBoss, sqljdbc.jar visibility

I am developing a rest api extension similar to the rest-api-sql-data-source example ( https://github.com/Bonitasoft-Community/rest-api-sql-data-source)
We use the Jboss bundle.
Due to limitations (sqlserver store procedure calls) I am not using the groovy.sql method, but the classic java approach.
So, in order to create the connection I have:

[Bonita 7] REST API Extensions always responds with HTTP 403


I'm currently experimenting with the extensions examples provided with Bonita 7.0.0. When I send a GET request on ../API/extension/demo/getExample I always get a HTTP 403 response. Of course, I've logged in before performing the request (I got HTTP 401 when I'm not logged). I'm testing it using Postman, a Chrome extension for testing REST API. I'm pretty sure it's a problem with the REST API authorization settings in Bonita, but I don't understand how it works.