Hello @Steven Morales Fallas

There is no specific place in website where a button directly calls a python function.

but, you can go achieve it in the following ways:

1. Add button click event in js file 
- Please refer to this link for how to add js in odoo: https://www.odoo.com/documentation/16.0/developer/reference/frontend/javascript_reference.html

2. You will need to write json rpc method in js for which you can call the python function
- Please refer to this link for how to add json rpc in odoo js: https://www.odoo.com/documentation/16.0/developer/reference/frontend/services.html?#rpc-service

I hope this will help you.

Thanks & Regards,
Email: odoo@aktivsoftware.com
Skype: kalpeshmaheshwari