Business Event not triggering the PLSQL procedure.. What to do?

Question

We need to call a plsql procedure when the GL Approval workflow has ended with approval. I thought i could do this by customizing the relevant business event.
We are on EBS 12.1.3 with RDBMS : 11.2.0.3.0.
I saw that the business event oracle.apps.gl.Journals.journal.approve was disabled currently. I enabled it and created a subscription for it. Subscription was a PLSQL procedure. Currently, for test purpose only thing it is doing is to insert a row into a table.
Business Event Subscription settings:
System: ORDEBS.SYSTEM.COM
Triggering Event
Source Type:Local
Event Filter: oracle.apps.gl.Journals.journal.approve
Execution Condition
Phase: 100
Status: Enabled
Rule Data: Message
Action Type:Custom
On Error: Stop and Rollback
Action
PL/SQL Rule Function: XX_GL_APPROVE_BE_PKG.Get_Attributes
Priority: Normal
Documentation (Not sure what value to be given for these. I went with the below values.)
Owner: Company Name
Owner Tag: Custom Schema
Using the below query i can see that the business event is getting called when the approval happens (One row added each time approval happened). But I cant see any rows in the table where it should insert a row. What could be going wrong? How can i verify that the procedure has been called?
select * from WF_DEFERRED where corrid ='APPS:oracle.apps.gl.Journals.journal.approve'
Procedure:
CREATE OR REPLACE PACKAGE BODY APPS.XX_GL_APPROVE_BE_PKG
AS
PROCEDURE Get_Attributes
IS
BEGIN
INSERT INTO xx.xx_test_table VALUES ('From BE');
COMMIT;
END Get_Attributes;
END XX_GL_APPROVE_BE_PKG;

Answer 1

Thanks Alejandro. Now this is working.
Changes i made:
1. Added the WFERROR workflow as a subscription to this event. So i could see that the function i am calling from the event did not have proper signature.
2. Changed the function signature to have standard parameters like:
CREATE OR REPLACE PACKAGE BODY XX_GL_APPROVE_BE_PKG
AS
function subscription(p_subscription_guid in raw,
p_event in out nocopy wf_event_t) return varchar2 is
l_result varchar2(20);
begin
insert into xxvtv.xxvtv_test_table values ('From BE');
commit;
exception
when others then
wf_core.context('XX_GL_APPROVE_BE_PKG','function subscription', p_event.getEventName(), p_event.getEventKey());
wf_event.setErrorInfo(p_event, 'ERROR');
return 'ERROR';
end subscription;
END XX_GL_APPROVE_BE_PKG;
3. Changed the owner name and owner tag both to the custom schema name (XX)