using ajax url to call php file

one text

Solution:

Assuming the website is visible at h???????ze.com and not h??????ze.com/public_html your URL should be /wp-content/plugins/buddyboss-platform/bp-templates/bp-nouveau/buddypress/activity/user-duration.php

public_html is the root of your website and will contain index.php so you need to point it there. The browser has no access to anything before this in the URL you are using.