Bitrix. Payment for the order with the choice of which specific part of the amount you need to allocate from the internal account. How to implement?

Question

PHP

Tagb: Bitrix, php
The task is to allow the user to set a part of the amount from the internal account, with which he could pay part of the order amount.
Now, when choosing "Pay from internal account", if the order amount is greater than the amount of internal. accounts, the latter is reset to zero.
The template is ready, I need to hook the event somewhere, and process the PAY_HOW_TO_PAY_FROM_ACCOUNT parameter accordingly,
so that when the payment or order is canceled, the money is returned to the internal account. user account.
Tell me what events need to be processed and how, if possible, in more detail.
I'm only for if you throw in similar examples, links.
I 'm using the checkout form: sale.order.ajax
Tried to handle events from here:dev.1c-bitrix.ru /api_help/sale/events/events_comp... but without success.
Thanks in advance.

Answer 1

This is Bitrix - contact support

Answer 2

similar task. payment occurs with a discount coupon, and then in the event the discount is removed and payment is added from the internal account. julianapriz.ru/internet-magazin-na-1s-bitriks-zame...