Gazelle/sections/api/preview.php

<?php
#declare(strict_types=1);

/* AJAX previews, simple stuff */
Text::$TOC = true;

if (!empty($_POST['AdminComment'])) {
    echo Text::full_format($_POST['AdminComment']);
} else {
    $Content = $_REQUEST['body']; // Don't use URL decode
    echo Text::full_format($Content);
}