Integration of Bitrix24 and Roistat

The situation is as follows
We have connected our websites (OpenCart v1.5.4.1) to the Roistat analytics system.
Roistat assigns each visitor a unique ID (the site displays as a promo code), to which you can associate the actions of the visitor (for example. Filling in op. Forms. All completed data in the forms (leads) are currently sent to the post office.

It is necessary to implement a tool that will link the entered promo code on bitrix24 in the transaction / lead card with the same value in Roistat, in order to eventually track the effectiveness of ads in Kazakhstan by one of the requirements:
A) manual (you will need to manually create leads in bitrix24 and manually enter a promotional code)
B) data from CTA forms and cart design will be sent directly to Bitrix24, and leads will be created automatically.

In the response, be sure to indicate:
1. What do you suggest to solve the problem?
2. Time frame for implementation
3. Cost of implementation

Payment upon the fact of work performed on Kiwi or YandexMoney