When it comes to paying off an order, you can either let the installments be charged on their scheduled due dates, or you can pay them off early.
Paying installments off early can often increase your likelihood of getting approved for new orders, however, it is not required. There is no punishment for paying your installments off as scheduled.
To pay off an installment early, simply login to your Sezzle dashboard, select "Manage Order" next to the order you'd like to make a payment on, and then click "Pay Now" next to the installment. Clicking that will make the payment immediately, and you can do this for any and all installments that you'd like to pay off.