Previously, we must register the delivery on account in the Client > "Balance" tab > Account movements > Delivery on account.
When generating the invoice, you must indicate in the field Payment method "Available on account", it will indicate us the amount that the customer has.
Go to the Receipts taband click on the receipt. You must indicate in the payment method field, "Available on account"and in the field Amount, you have to indicate the amount we want to register on the receipt.
When you check Collected and click on Save, 2 receipts will be generated, one with the amount of the delivery on account and the other with the amount receipt.
On the Customer > tab; Balance > tab; Account movements, the amount that was indicated on the receipt will be deducted.
You will be able to check the amount of this Available on account, in the same Balance tab.