How fix error in the WordPress loop?

Question

I do not fulfill the condition for the appearance of the button below, what do I do wrong?

<?php
                query_posts( array(
                    'post_type' => 'post',
                    'post_per_page' => 6,
                    ) );
                if( have_posts() ){
                    while( have_posts() ){
                        the_post();
                        ?>
                        <div class="project">
                            <a href="<?php echo get_permalink(); ?>"><div class="project-img" style="background: url('<?php echo get_the_post_thumbnail_url(); ?>')"></div></a>
                            <span><?php the_title(); ?></span>
                            <?php the_excerpt(); ?>
                            <p class="post-date"><?php the_date('d/m/Y'); ?></p>
                        </div>
                        <?php
                    }
                } else {

                }
                ?>
<?php if (  $wp_query->max_num_pages > 1 ) : ?>
<script>
var ajaxurl = '<?php echo site_url() ?>/wp-admin/admin-ajax.php';
var true_posts = '<?php echo serialize($wp_query->query_vars); ?>';
var current_page = <?php echo (get_query_var('paged')) ? get_query_var('paged') : 1; ?>;
var max_pages = '<?php echo $wp_query->max_num_pages; ?>';
</script>
<div id="true_loadmore">Загрузить ещё</div>

Answer 1

You've set 'posts_per_page' => -1,, which means unlimited posts per page, but are checking $wp_query->max_num_pages > 1. There's never going to be more than 1 page if you have unlimited posts per page.