archive_thread
This function is equivalent of deleting the conversation by user. Its only hides the conversation from the conversations list, but it not actually deleted from database and can be restored later
REQUIREMENTS
To be able to implement this guide, you need to learn how to insert PHP snippets to your website.
You can find guide here: WP Beginner
<?php
$user_id = 3;
$thread_id = 6610;
Better_Messages()->functions->archive_thread( $user_id, $thread_id );