diff --git a/README.md b/README.md
index 8bde85f..68b8858 100644
--- a/README.md
+++ b/README.md
@@ -61,12 +61,11 @@ This **open-source plugin was developed to help the Sylius community**. If you h
 4. Add routing to sylius_shop.yml:
     ```yaml
     sylius_shop_checkout_start:
-       path: /{_locale}/checkout-start
+       path: /
        methods: [GET]
        defaults:
            _controller: bitbag_sylius_amazon_pay_plugin.controller.action.checkout_start
-       requirements:
-           _locale: ^[a-z]{2}(?:_[A-Z]{2})?$  
+
    ```
 5. Please add the Webpack build configuration to your `config/packages/webpack_encore.yaml` file:
 
diff --git a/src/Controller/Action/AmazonPayStartAction.php b/src/Controller/Action/AmazonPayStartAction.php
index d25fabe..20c2e1f 100644
--- a/src/Controller/Action/AmazonPayStartAction.php
+++ b/src/Controller/Action/AmazonPayStartAction.php
@@ -35,7 +35,7 @@ public function __construct(Environment $templating)
     public function __invoke(Request $request): Response
     {
         return new Response(
-            $this->templating->render('BitBagSyliusAmazonPayPlugin:AmazonPay:amazonPayStart.html.twig')
+            $this->templating->render('@BitBagSyliusAmazonPayPlugin/AmazonPay/amazonPayStart.html.twig')
         );
     }
 }
diff --git a/src/Controller/Action/CheckoutStartAction.php b/src/Controller/Action/CheckoutStartAction.php
index 9dcfd17..837bbb9 100644
--- a/src/Controller/Action/CheckoutStartAction.php
+++ b/src/Controller/Action/CheckoutStartAction.php
@@ -54,7 +54,7 @@ public function __invoke(Request $request): Response
         $order = $this->cartContext->getCart();
 
         /** @var PaymentMethodInterface $paymentMethod */
-        $paymentMethod = $order->getLastPayment()->getMethod();
+        $paymentMethod = $order->getLastPayment()?->getMethod();
 
         if (
             null !== $paymentMethod &&
diff --git a/src/Resources/views/AmazonPay/AddressBook/_widget.html.twig b/src/Resources/views/AmazonPay/AddressBook/_widget.html.twig
index 9e3bc2d..063de1a 100644
--- a/src/Resources/views/AmazonPay/AddressBook/_widget.html.twig
+++ b/src/Resources/views/AmazonPay/AddressBook/_widget.html.twig
@@ -1,4 +1,4 @@
-{% include '@SyliusUi/_javascripts.html.twig' with {'path': 'assets/shop/js/app.js'} %}
+{{ encore_entry_script_tags('app-shop-entry', null, 'app.shop') }}
 
 <link href="{{ asset('bundles/bitbagsyliusamazonpayplugin/css/Widgets.css') }}" rel="stylesheet">
 
diff --git a/src/Resources/views/AmazonPay/Summary/_widget.html.twig b/src/Resources/views/AmazonPay/Summary/_widget.html.twig
index d4c2965..92e5365 100644
--- a/src/Resources/views/AmazonPay/Summary/_widget.html.twig
+++ b/src/Resources/views/AmazonPay/Summary/_widget.html.twig
@@ -1,7 +1,7 @@
 <div id="readOnlyAddressBookWidgetDiv"></div>
 <div id="readOnlyWalletWidgetDiv"></div>
 
-{% include '@SyliusUi/_javascripts.html.twig' with {'path': 'assets/shop/js/app.js'} %}
+{{ encore_entry_script_tags('app-shop-entry', null, 'app.shop') }}
 
 <link href="{{ asset('bundles/bitbagsyliusamazonpayplugin/css/Widgets.css') }}" rel="stylesheet">
 
diff --git a/src/Resources/views/AmazonPay/Wallet/_widget.html.twig b/src/Resources/views/AmazonPay/Wallet/_widget.html.twig
index c5e93c7..410a9d1 100644
--- a/src/Resources/views/AmazonPay/Wallet/_widget.html.twig
+++ b/src/Resources/views/AmazonPay/Wallet/_widget.html.twig
@@ -1,6 +1,6 @@
 <div id="walletWidgetDiv"></div>
 
-{% include '@SyliusUi/_javascripts.html.twig' with {'path': 'assets/shop/js/app.js'} %}
+{{ encore_entry_script_tags('app-shop-entry', null, 'app.shop') }}
 
 <link href="{{ asset('bundles/bitbagsyliusamazonpayplugin/css/Widgets.css') }}" rel="stylesheet">
 
diff --git a/src/Resources/views/AmazonPay/amazonPayStart.html.twig b/src/Resources/views/AmazonPay/amazonPayStart.html.twig
index c71a26c..a5a2463 100644
--- a/src/Resources/views/AmazonPay/amazonPayStart.html.twig
+++ b/src/Resources/views/AmazonPay/amazonPayStart.html.twig
@@ -1,5 +1,3 @@
-{% include '@SyliusUi/_javascripts.html.twig' with {'path': 'assets/shop/js/app.js'} %}
-
 <script>
     function getURLParameter(name, source) {
         return decodeURIComponent((new RegExp('[?|&|#]' + name + '=' +
@@ -8,17 +6,21 @@
         ;
     }
 
-    let accessToken = getURLParameter("access_token", location.hash);
+    let accessToken = getURLParameter('access_token', location.hash);
 
     if (typeof accessToken === 'string' && accessToken.match(/^Atza/)) {
         document.cookie = "amazon_Login_accessToken=" + accessToken;
     }
 
-    $.post('{{ path('bitbag_sylius_amazon_pay_initialize') }}', {
-        accessToken: accessToken
-    }).done(function (data) {
+    let formData = new FormData();
+    formData.append('accessToken', accessToken);
+
+    fetch('{{ path('bitbag_sylius_amazon_pay_initialize') }}', {
+        method: 'POST',
+        body: formData
+    }).then(function (data) {
         window.location.replace("{{ path('sylius_shop_checkout_address') }}" + location.hash);
-    }).fail(function (data) {
+    }).catch(function (data) {
         {#window.location.replace("{{ path('sylius_shop_cart_summary') }}");#}
     });
 </script>
diff --git a/src/Twig/Extension/RenderSummaryWidgetExtension.php b/src/Twig/Extension/RenderSummaryWidgetExtension.php
index 4497646..69e46be 100644
--- a/src/Twig/Extension/RenderSummaryWidgetExtension.php
+++ b/src/Twig/Extension/RenderSummaryWidgetExtension.php
@@ -61,7 +61,7 @@ public function renderSummaryWidget(): string
         $order = $this->cartContext->getCart();
 
         /** @var PaymentMethod $paymentMethodCurrent */
-        $paymentMethodCurrent = $order->getLastPayment()->getMethod();
+        $paymentMethodCurrent = $order->getLastPayment()?->getMethod();
 
         if (
             null === $paymentMethodCurrent ||