The payment form is a set of fields with information about a payment and an order. The form is shown in the store's interface on the page that the user sees after placing an order. You can get the code for the form during activation, or you can create the form yourself.
When the user clicks the Pay button, a set of payment parameters is sent to Yandex.Checkout at https://money.yandex.ru/eshop.xml (POST method). The merchant can add more parameters to the form.
When the user sends the form, it initiates the process of generating and processing the transfer on Yandex.Checkout's side.
There are two payment flows: the main flow where the payment method is selected on Yandex.Checkout's side, and flow where the payment method is selected on the merchant's site.
Form for choosing the payment method in Yandex.Checkout
Don't specify the payment method in this form. Pass an empty value in the paymentType parameter (paymentType="").
All the payment methods available to this merchant will automatically appear in Yandex.Checkout. New payment methods will be added automatically.
Form for choosing payment method on merchant's website
In this case, the form should specify all the payment methods that are available to this merchant. The user's selection is transmitted to the Yandex.Checkout service (in the paymentType parameter).
The merchant is responsible for the payment method selection in the store's interface. To add a new payment method, the merchant must make changes to the payment form.
To avoid making users enter their phone numbers and email addresses twice, we recommend transmitting this data to Yandex.Checkout with the payment information (in the cps_phone and cps_email parameters).