Payment Request 
You can show business transactions that lead to payments using this function. Every payment request contains at least one FI document in which one FM account assignment and one vendor is assigned. In contrast to the functionality delivered as standard in the Financial Accounting component, an FI document may only contain a single subledger account line.
You define to which extent you want to use the request functions in the Customizing of the Funds Management Local Government component in section Requests in Maintain Global Settings .
The procedure in payment and acceptance requests is practically the same. That is why the description of this function was grouped together under payment request.
For more, read Entry and Approval of Payment Requests