BuddyPress.org

It uses the “plugin-template.php” file.

It’s a generic catch-all for plugins, which need a layout for their settings.

Look for it in /wp-content/wp-sn-parent/.

If you’re using a child theme, copy that file to your child theme folder.

More info:

https://buddypress.org/forums/topic/which-template-file-is-settings