Hello, if you want to sell goods or services using your own web resource, you need to think about how the user will make a purchase. The easiest way is to leave a request for a call with the manager or provide an opportunity to place an order, but not pay for it immediately through the site. However, this method has one significant drawback: the loss of conversion. The integration of payment systems allows the client to immediately provide payment methods and make a purchase instantly. If you are interested, then at payadmit.com you can read information about one of the best providers of payment systems.