When you are about to register payments, you first enter payment settings in the upper part of the window.
The cursor is first located in the Payment date field, then you enter the Payment method, Account, Batch total and Text. By entering the Customer code, the PopUp feature in the Invoice number field under Mark to pay will only search for unpaid invoices from the customer in question.
As new invoices are moved to the Marked to pay section, you will see information regarding Batch rest, Paid quantity, Total paid, as well as a button to see the Accounting order.
At the top of the window, to the left, you can see the Batch number in question. If you load a previously registered batch, you will see the batch's Ledger number / Voucher number.