Code I got from Joe to do stuff.

snippet.php

<?php
// Download this snippet as a plugin and more at: https://wordbits.io/snippet/paginate-pages/
// Created by: Liam Dempsey
?>

<?php
function paginate_child_pages( $post ) {
  $page_id = $post->ID;
  
  $args = array(
    'post_type'      => 'page',
    'posts_per_page' => -1,
    'post_parent'    => $page_id,
    'order'          => 'ASC', //change to fit your order
    'orderby'        => 'menu_order', //change to fit your order
 	);


	$child_pages = new WP_Query( $args );

	if ( $child_pages->have_posts() ) {
		$pagination = '<ul class=