wp_ulike_count_box_template filter

I am trying to remove “0” using –

add_filter(‘wp_ulike_count_box_template’, ‘wp_ulike_change_my_count_box_template’, 10, 2);function wp_ulike_change_my_count_box_template($string, $counter) {
$num = preg_replace(“/[^0-9,.]/”, “”, $counter);
if($num == 0) return;
else return $string;
}

Is the filter added to ‘inc/classes/class-ulike.php” file ? If not where would this filter go ? Thanks.