How to create approval for service type document

Hello,

I am trying to create a Approval Query wherein if a Patricular User creates a SERVICE Type AP Invoice then it should go for approval.

I used the query :

SELECT distinct 'TRUE' FROM OPCH T0 INNER JOIN PCH1 T1 ON T0.[DocEntry] = T1.[DocEntry] WHERE T0.[DocType] ='S'

But the problem is that when the above user is making ITEM Type AP Invoice then also its going for approval.

Please advise.

Kind Regards,

Ravi