Hello. Currently it is not possible in VM Invoice. You can create order manually (by VM front-end or from VM Invoice in back-end), generate invoice and send it to customer as quote. But payment AFTER order was created is not as simple. It is matter rather of VM component and plugins. I belive there are more users that requests this feature for VM. Like user will log in and see his unpaid orders and ability to pay for order that was already created. But we currently do not support this feature in VM Invoice. It should be developed by other VM developers.
