payement customer : problem with document RU - key UB

first sorry for my english, I write from Belgium
I'm a beginner with JDE - Enterprise One
I have a problem to input a payment of a customer
There were pre-payments before, and JDE Enterpriseone give a document type RU with key GL UC to these payments
When I want to settle the customer account with a final payment; these prepayement don't appear and dus I can not select all my account ?
How to solve that ? change the document type ? the key ?
Thanks in advance

I'm not completely clear on what you are trying to accomplish based on the info provided, but I assume you are trying to select RU invoices in the invoice match step? I don't think this is possible, since the RU invoices represent open receipts. I would first review all your open receipts for a client, and use those to apply any outstanding invoices first. You will find your RU invoices close as you follow this process. Once all your non RU invoices are applied, you can create a debit memo in invoice entry to clear the remaining unapplied cash from receipt entry.