Loop all post on single.php

I have CPT called post-author that have 'has_archive' => true.

In single-post-author.php I want to display author info with custom fields, and then show all of his posts with pagination.

Code below works and display posts and number on pages, but when I go to the next page its 404 or redirects me to the same page. Also this code works in archive.php.

If I put this code to single.php it lists posts with pagination numbers, but when I want to go to the next page it redirects me to page 0, even if i typu manually /page/2.

<?php
    $args = array(
        'post_type' => 'post',
        'posts_per_page' => 4,
        'paged' => $our_current_page
    );

    $post_query = new WP_Query($args);

    if($post_query->have_posts() ) {
        while($post_query->have_posts() ) {
            $post_query->the_post();
            ?>
                <h4><?php the_title(); ?></h4>
            <?php
        }
    } 
        
    echo paginate_links(array(
        'total' => $post_query->max_num_pages
    ));
?>