Website Direct Payment

How can I accept payment from my website…through my pay now buttons? To click a pay now or buy now button on any pricing package and get to the invoice ninja payment form from from my website… I have a form to fill out for the order, then click submit…to send in the request, now after clicking on submit, the form can transfer the client to another page…can this page send the person to a link related to amount and product submitted on the form…and they can pay?..

Sorry, buy now links only support selling a single product