Display child term of current parent taxonomy term


I would like to display child terms according to my current taxonomy parent term. So we have tree like this:

In taxonomy.php I want to display child terms of current taxonomy. So if I am in Term 1 page there should be listed subterms of Term 1 term. But when I am in “Sub term” there should be listet posts according to this term.

I have 50% done. Found code here

Here is my page: http://manx89.ssd-linuxpl.com/sauny/index.php/kategoria_produktu/sauny/

We are in “Sauny” parent term and bellow are listed child terms. If you click it, there should list posts. But there is only one newest post. How to display all of them?

                                <?php
    $current = $wp_query->get_queried_object();
    $current_term_id = $current->term_id;
    $current_name = $current->name;
    $current_taxonomy = $current->taxonomy;
    $current_parent = $current->parent;

    echo '<h1>'.$current_name.'</h1>';
    echo '<div class="kategoria-desc">'. term_description() .'</div>';
    $sub_terms = get_terms( array(
        'taxonomy'      => $current_taxonomy,

        'parent'        => $current_term_id,
        'hide_empty'    => false,
    ) );
                        

    if ($sub_terms) {
        echo '<div class="sub-terms">';
        foreach ($sub_terms as $sub_term) {

            echo '<div class="col-md-4 boks-kategoria-tax"><a href="'. get_term_link( $sub_term ) .'">' ;
            echo '<div style="background:url('. z_taxonomy_image_url($sub_term->term_id) .')" class="inner-boks">';
            echo '<div class="inner-boks-name">'.$sub_term->name.'</div>';
            echo '<div class="inner-boks-opis">'. $sub_term->description .'</div>';
            echo '</div>';
            echo '</a></div>';
        }// END foreach
        echo '</div><!-- END .sub-terms -->';

    } else {
        echo '<div class="boks-produkt col-md-3">';
        echo '<a href="'. get_permalink() .'">' ;
        echo the_title();
        echo the_post_thumbnail();
         echo '</a>';
        echo '</div>';
    } ?>

Can You help me with modify this code?
Thx a lot