Sends an email notification when a comment receives a reply - WordPress

functions.php

<?php

/* Based on: https://wordpress.org/plugins/comment-reply-email-notification/ */
add_action('wp_insert_comment',    'qr_comment_notification',  99, 2);
add_action('wp_set_comment_status','qr_comment_status_update', 99, 2);
add_filter('wp_mail_content_type', function($contentType) { return 'text/html'; });

/**
 * Sends an email notification when a comment receives a reply
 * @param  int    $commentId The comment ID
 * @param  object $comment   The comment object
 * @return boolean
 */
function qr_comment_notification($commentId, $comment) {
    if ($comment->comment_approved == 1 && $comment->comment_parent > 0) {
        $parent = get_comment($comment->comment_parent);

        $body  = __('Hi ', 'cren-plugin') . $parent->comment_author . ',';
        $body .= '<br><br>' . $comment->comment_author . __(' has replied to your comment on ', 'cren-plugin');
        $body .= '<a href="' . get_permalink($parent->comment_post_ID) . '">' . get_the_title($parent->comment_post_ID) . '</a>';
        $body .= '<br><br><em>"' . esc_html($comment->comment_content) . '"</em>';
        $body .= '<br><br><a href="' . get_comment_link($parent->comment_ID) . '">' . __('Click here to reply', 'cren-plugin') . '</a>';

        $email = $parent->comment_author_email;
        $title = '[QROkes] ' . __('New reply to your comment', 'cren-plugin', $body);
		    $headers = 'From: MyName <noreply@mydomain.com>';
		
        wp_mail($email, $title, $body, $headers);
    }
}

/**
 * Sends a notification if a comment is approved
 * @param  int    $commentId     The comment ID
 * @param  string $commentStatus The new comment status
 * @return boolean
 */
function qr_comment_status_update($commentId, $commentStatus) {
    $comment = get_comment($commentId);

    if ($commentStatus == 'approve') {
        cren_comment_notification($comment->comment_id, $comment);
    }
}