Your credit account invoices will be listed in Koho on the Invoice page.
There you will find a table with all your shipment invoices, the credit account invoices will be part of that list. The credit account invoices will have the status of "View in Credit Account". You can click on that row in the table to be taken to your credit account. There you can see all of your credit account invoices and pay them.
From your Credit Account you will need to check which invoice you wish to pay. Then the Pay button at the top of the invoice table will become blue and enabled.
Click the "Pay" button. A dialog will open showing you the amount and the payment method. You will need to confirm that you wish to make a payment by clicking the blue "Pay" button on the left.
You will now see a confirmation dialog about your payment. Please allow 1-2 business days for this payment to reflect in your account.
You will need to have your payment method setup before you can make a payment. How to setup my payment method.