How to add a field to a Buddypresss activity?

Question

WordPress

Hello!
Please help me solve this problem with Buddypress.
Add an addon to the activity form. fields. The form itself is located in activity/post-form.php
It's not a problem to add the inputs themselves. It is necessary that these fields be saved in the database when sending. I've been looking for actions and hooks for the whole day.
Maybe Buddypress already has built-in functionality for additional. fields or is there some plugin?