how to update shopware 5 total price by value in cart

Question

Hello i am working on a Shopware 5 project, where i am making an ajax request from my confirm.tpl page

    <form id="taxer">
    <input type="hidden" id="csrf-token" value="{$sCsrfToken}">

        <div class="accept-zero-percent-checkbox">
            {if $smarty.session.Shopware.bZeroTax|intval eq 1 }
                <input type="checkbox" id="accept-zero-percent" name="accept-zero-percent" checked="checked">
            {else}
                <input type="checkbox" id="accept-zero-percent" name="accept-zero-percent" >
            {/if}
    
        </div>
    </form>

<script src="https://code.jquery.com/jquery-3.6.4.min.js"></script>



{/block}

in my bootstrap

  $this->subscribeEvent(
            'Enlight_Controller_Dispatcher_ControllerPath_Frontend_Tax',
            'onGetTax'
        );

 public function onGetTax(Enlight_Event_EventArgs $args)
{
    return __DIR__ . '/Controllers/Frontend/TaxController.php';
}

In my Controller i declare my index action method to receive my form request and then try to process based on if the user has checked the box or not. if user is checked i call a method and vice versa.

 public function indexAction()
    {
        $basketService = $this->get('shopware.modules.sBasket');
        $cart = $basketService->sGetBasket();

        if ($isChecked) {
            $this->addTaxToCart($cart);
        } else {
            $this->removeTaxFromCart($cart);
        }
        $response = ['status' => 'success', 'data' => $requestData];

        $this->View()->loadTemplate('frontend/tax/index.tpl');
        $this->View()->assign('data', $response);
    }

     /**
     * Add 19% tax to the cart
     *
     * @param \Shopware\Models\Order\Basket $cart
     */
    private function addTaxToCart($cart)
    {
        foreach ($cart['content'] as &$item) {
            $price = $item['priceNumeric'];
            $taxRate = 0.19;
            $taxAmount = $price * $taxRate;

            $item['priceNumeric'] += $taxAmount;
            $item['price'] = number_format($item['priceNumeric'], 2, '.', ''); 
        }

        $this->get('shopware.modules.sBasket')->sRefreshBasket();
    }

    /**
     *
     * @param \Shopware\Models\Order\Basket $cart
     */
    private function removeTaxFromCart($cart)
    {
        foreach ($cart['content'] as &$item) {
            $price = $item['priceNumeric'];
            $taxRate = 0.19;
            $taxAmount = $price * $taxRate;
            $item['priceNumeric'] -= $taxAmount;
            $item['price'] = number_format($item['priceNumeric'], 2, '.', ''); 
        }
        $this->get('shopware.modules.sBasket')->sRefreshBasket();
    }

The ajax request is made but then i get this error

[2024-01-24T10:35:55.641798+01:00] core.CRITICAL: You have requested a non-existent service "core.basket".