alter/finish woocommerce invoice plugin for factuursturen

I am using woocommerce for my products, but i use [login to view URL] as invoice software. I have the api files that have been created by a company, but i do not know how to implement this into woocommerce. This plugin has been made for the following functions: When someone places an order in woocommerce, and the status of the order is "complete" it sends the order to factuursturen and makes an automatic invoice of this order. When you have a "virtual product", you need to manually put the order status to "complete". When this is done the order automaticly sends it to factuursturen where factuursturen again makes an automatic invoice. When possible it also needs to update the status on payment. When the order has been payed for with ideal (mollie) factuursturen needs to be updated with this status because factuursturen also works with ideal (mollie) Factuursturen has a API in English ([login to view URL]). For the realy API files you need to contact me.