How to organize automatic user registration?

Question

1C-Bitrix

How to organize automatic registration and generation of a username and password for a user?
Edition: small business (missing sale.order.ajax).
Scheme:

1. An authorized user, being on the page with the bitrix:news.list component, clicks on the button with the email of the future user in the data-email.
   
2. email post-request goes to the handler.
   
3. The mail event fires. An email with a username and password is sent to email (from data-email). An activated account is created.