Adding a column to woocomerce admin order page that can be sorted

I’m trying to add a column with custom meta data to my woocommerce admin order list and be able to sort them by name. So far I have found a code that adds the columns but they are not sortable. Can anyone help? Thanks!

Code that I found:

// ADDING 2 NEW COLUMNS WITH THEIR TITLES (keeping "Total" and "Actions" columns at the end)
add_filter( 'manage_edit-shop_order_columns', 'custom_shop_order_column', 20 );
function custom_shop_order_column($columns)
{
    $reordered_columns = array();

    // Inserting columns to a specific location
    foreach( $columns as $key => $column){
        $reordered_columns[$key] = $column;
        if( $key ==  'order_status' ){
            // Inserting after "Status" column
            $reordered_columns['my-column1'] = __( 'Razred','theme_domain');
            $reordered_columns['my-column2'] = __( '?ola','theme_domain');
        }
    }
    return $reordered_columns;
}

// Adding custom fields meta data for each new column (example)
add_action( 'manage_shop_order_posts_custom_column' , 'custom_orders_list_column_content', 20, 2 );
function custom_orders_list_column_content( $column, $post_id )
{
    switch ( $column )
    {
        case 'my-column1' :
            // Get custom post meta data
            $my_var_one = get_post_meta( $post_id, 'child_class', true );
            if(!empty($my_var_one))
                echo $my_var_one;

            // Testing (to be removed) - Empty value case
            else
                echo '<small>(<em>no value</em>)</small>';

            break;

        case 'my-column2' :
            // Get custom post meta data
            $my_var_two = get_post_meta( $post_id, 'child_school', true );
            if(!empty($my_var_two))
                echo $my_var_two;

            // Testing (to be removed) - Empty value case
            else
                echo '<small>(<em>no value</em>)</small>';

            break;
    }
}
woocommerce-offtopic