Modifying the comment editing time doesn't work

Hi !

I have followed the instructions from the FAQ page of your plugin to adjust the comment time, but it unfortunately doesn’t work.
I am using a child theme, and I created a file functions.php to change that (I had no file functions.php in my child theme yet)

Here is the code of my functions.php file :

<?php
//Simple Comment Editing
add_filter( 'sce_comment_time', 'edit_sce_comment_time' );
function edit_sce_comment_time( $time_in_minutes ) {
    return 30;
}

Many thanks for your help !

https://www.ads-software.com/plugins/simple-comment-editing/