Integration of the payment system b2pay.io a template to the tilda site via API

Task:
Integrate the payment system b2pay.io to the site on the tilda template through the API

Description:
There is a payment system, there is a ready-made website. On the page, the b2pay.io has an installation guide, a link on request to the executor. The personal account in the admin panel of the payment system is also ready. Interested in the timing and cost of the order