Assembly Options at checkout

Question

I want to add Assembly options at the checkout page like this https://imgur.com/a/WrzWCiO

Anyone knows how to do it without plugin? Thanks

add_action('woocommerce_after_order_notes', 'custom_checkout_fields');

function custom_checkout_fields($checkout) {
    echo '<div id="custom_checkout_fields"><h2>' . __('Additional Services') . '</h2>';

woocommerce_form_field('assembly_option', array(
        'type' => 'select',
        'class' => array('form-row-wide'),
        'label' => __('Assembly Service'),
        'required' => false,
        'options' => array(
            '' => __('None'),
            'individual_item' => __('Assembly for an Individual Item (+$200)'),
            'set' => __('Assembly for a Set (+$600)'),
        )
    ), $checkout->get_value('assembly_option'));

    woocommerce_form_field('trash_removal_option', array(
        'type' => 'select',
        'class' => array('form-row-wide'),
        'label' => __('Trash Removal Service'),
        'required' => false,
        'options' => array(
            '' => __('None'),
            'individual_item' => __('Trash Removal for an Individual Item (+$50)'),
            'set' => __('Trash Removal for a Set (+$150)'),
        )
    ), $checkout->get_value('trash_removal_option'));

    echo '</div>';
}


add_action('woocommerce_checkout_create_order', 'custom_checkout_field_update_order_meta');

function custom_checkout_field_update_order_meta($order) {
    if (!empty($_POST['assembly_option'])) {
        $order->update_meta_data('assembly_option', sanitize_text_field($_POST['assembly_option']));
    }
    if (!empty($_POST['trash_removal_option'])) {
        $order->update_meta_data('trash_removal_option', sanitize_text_field($_POST['trash_removal_option']));
    }
}


add_action('woocommerce_cart_calculate_fees', 'add_assembly_trash_removal_cost');

function add_assembly_trash_removal_cost() {
    if (is_admin() && !defined('DOING_AJAX')) return;

    $assembly_option = WC()->session->get('chosen_assembly_option');
    $trash_removal_option = WC()->session->get('chosen_trash_removal_option');

    if ($assembly_option) {
        switch ($assembly_option) {
            case 'individual_item':
                $assembly_cost = 200;
                break;
            case 'set':
                $assembly_cost = 600;
                break;
            default:
                $assembly_cost = 0;
        }
        WC()->cart->add_fee(__('Assembly Service', 'text-domain'), $assembly_cost);
    }

    if ($trash_removal_option) {
        switch ($trash_removal_option) {
            case 'individual_item':
                $trash_removal_cost = 50;
                break;
            case 'set':
                $trash_removal_cost = 150;
                break;
            default:
                $trash_removal_cost = 0;
        }
        WC()->cart->add_fee(__('Trash Removal Service', 'text-domain'), $trash_removal_cost);
    }
}


add_action('woocommerce_checkout_update_order_review', 'update_session_with_selected_options');

function update_session_with_selected_options($posted_data) {
    if (isset($posted_data['assembly_option'])) {
        WC()->session->set('chosen_assembly_option', $posted_data['assembly_option']);
    }
    if (isset($posted_data['trash_removal_option'])) {
        WC()->session->set('chosen_trash_removal_option', $posted_data['trash_removal_option']);
    }
}