How to create pagination on archive.php template

I’m creating a custom theme and I’m struggling to get pagination working on my archive.php template.

I’ve tried to adapt the code I’m using on my main blog page, but it’s simply displaying all blog posts rather than just those with a certain tag or category.

Any ideas where I’m going wrong and how to get the archive.php template working as it should be WITH pagination?

Thanks in advance,

Tom

<?php get_header(); ?>

    <!-- PAGE INTRODUCTION -->
    <div class="container">
        <h1 class="page_title"><?php the_archive_title(); ?></h1>
    </div>

    <!-- PAGE CONTENTS -->
    <div class="container">
        <div class="row">
            <?php 
                $paged = ( get_query_var('paged') ) ? get_query_var('paged') : 1;
                $custom_args = array(
                    'post_type' => 'post',
                    'posts_per_page' => 10,
                    'paged' => $paged
                );
                $custom_query = new WP_Query( $custom_args ); 
            ?>
            <?php if( $custom_query->have_posts() ) : while( $custom_query->have_posts() ) : $custom_query->the_post(); ?>
                <div class="item">
                    <h3><?php the_title(); ?></h3>
                    <a href="<?php the_permalink(); ?>">Read more</a>
                </div>
            <?php endwhile; endif; wp_reset_postdata(); ?>
        </div>

        <!-- PAGINATION -->
        <?php
            if (function_exists(custom_pagination)) {
                custom_pagination($custom_query->max_num_pages,"",$paged);
            }
        ?>

    </div>

<?php get_footer(); ?>