Anonymous Comments Form (Wordpress plugin) - Disables email, url and author fields on comments form.

anonymous-comments-form.php

<?php
/*
 * Plugin Name:     Anonymous Comments Form
 * Description:     Disables email, url and author fields on comments form.
 * Version:         1.0
 * Author:          Emilio Rubio Rigo
 * Author URI:      https://emilioblog.com
 * License:         GPLv3
 * License URI:     https://www.gnu.org/licenses/gpl-3.0.html
 */

add_filter('comment_form_field_email', '__return_false');
add_filter('comment_form_field_url', '__return_false');
add_filter('comment_form_field_author', '__return_false');