WooCommerce Products per page dropdown

functions.php

<?php

add_action( 'woocommerce_before_shop_loop', 'yanco_products_per_page_selectbox', 25 );
function yanco_products_per_page_selectbox() {
    $html = '';
    
    $style = 'font-size: 16px;
    font-weight: 300;
    font-family: inherit;
    letter-spacing: 1px;
    text-transform: uppercase;
    width: 289px;
    text-align: right;
    background-color: #355477;
    color: white;';

    $per_page = filter_input( INPUT_GET, 'perpage', FILTER_SANITIZE_NUMBER_INT );     

    $orderby_options = array(
        '12' => '12 produkter per side',
        '20' => '20 produkter per side',
        '40' => '40 produkter per side',
        '64' => '64 produkter per side',
    );

    $html .= '<div class="woocommerce-perpage" style="text-align: right;">';
        $html .=  '<select style="' . $style . '" onchange="if (this.value) window.location.href=this.value">';       
            foreach( $orderby_options as $value => $label ) {

                $per_page_value = '';
                
                if ( isset( $_GET['orderby'] ) ) {
                    $per_page_value = $value . '&orderby=' . $_GET['orderby'];
                } else {
                    $per_page_value = $value;
                }
                
                $html .= '<option ' . selected( $per_page, $value ) . ' value="?perpage=' . $per_page_value . '#main-archive-products">' . $label. '</option>';                
                
            }
        $html .= '</select>';
    $html .= '</div>';

    echo $html;
}

add_action( 'pre_get_posts', 'yanco_products_per_page_pre_get_posts', 200 );
function yanco_products_per_page_pre_get_posts( $query ) {
    $per_page = filter_input( INPUT_GET, 'perpage', FILTER_SANITIZE_NUMBER_INT );     
    
    if( $query->is_main_query() && !is_admin() && is_product_category() ) {
        $query->set( 'posts_per_page', $per_page );
    }
}