diff --git a/BitCart.php b/BitCart.php
new file mode 100644
index 0000000..f6d496e
--- /dev/null
+++ b/BitCart.php
@@ -0,0 +1,106 @@
+<?php
+// https://github.com/bitcart/whmcs-plugin/blob/master/modules/gateways/bitcartcheckout.php
+// https://github.com/bitcart/bitcart-fossbilling/blob/master/Bitcart/Bitcart.php
+
+namespace App\Extensions\Gateways\BitCart;
+
+use App\Classes\Extensions\Gateway;
+use App\Helpers\ExtensionHelper;
+use Illuminate\Support\Facades\Http;
+
+class BitCart extends Gateway
+{
+    /**
+    * Get the extension metadata
+    *
+    * @return array
+    */
+    public function getMetadata()
+    {
+        return [
+            'display_name' => 'BitCart',
+            'version' => '0.0.1',
+            'author' => '0ut0f.space',
+            'website' => 'https://0ut0f.space',
+        ];
+    }
+
+    /**
+     * Get all the configuration for the extension
+     *
+     * @return array
+     */
+    public function getConfig()
+    {
+        return [
+          [
+            'name' => 'api_endpoint',
+            'friendlyName' => 'BitCart API endpoint',
+            'type' => 'text',
+            'required' => true,
+           ],
+           [
+                'name' => 'store_id',
+                'friendlyName' => 'BitCart store id',
+                'type' => 'text',
+                'required' => true,
+           ],
+           [
+                'name'=>'admin_url',
+                'friendlyName' => 'BitCart admin URL',
+                'type' => 'text',
+                'required' => true,
+           ],
+        ];
+    }
+
+    /**
+     * Get the URL to redirect to
+     *
+     * @param int $total
+     * @param array $products
+     * @param int $invoiceId
+     */
+    public function pay($total, $products, $invoiceId)
+    {
+        $payment_url = $this->get_payment_url($invoiceId,$total);
+        return $payment_url;
+    }
+
+    public function get_payment_url ($invoiceId, $amount) {
+        $api_domain = ExtensionHelper::getConfig('Bitcart', 'api_endpoint');
+        $admin_domain = ExtensionHelper::getConfig('Bitcart','admin_url');
+        $params = array(
+            'price' => number_format($amount, 2, '.', ''),
+            'store_id' => ExtensionHelper::getConfig('Bitcart','store_id'),
+            'currency' => ExtensionHelper::getCurrency(),
+            'email' => auth()->user()->email,
+            'redirect_url' => route('clients.invoice.show', $invoiceId),
+            'order_id' => $invoiceId,
+        );
+        $invoice = $this->send_request(sprintf('%s/%s', $api_domain, 'invoices/order_id/' . urlencode($invoiceId)), $params);
+        return $admin_domain . '/i/' . $invoice->id;
+    }
+
+    public function send_request($url, $data, $post = 1)
+    {
+        $post_fields = json_encode($data);
+
+        $request_headers = array();
+        $request_headers[] = 'Content-Type: application/json';
+
+        $ch = curl_init();
+        curl_setopt($ch, CURLOPT_URL, $url);
+        curl_setopt($ch, CURLOPT_HTTPHEADER, $request_headers);
+        if ($post) {
+            curl_setopt($ch, CURLOPT_POST, $post);
+            curl_setopt($ch, CURLOPT_POSTFIELDS, $post_fields);
+        }
+        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+        $result = curl_exec($ch);
+
+        curl_close($ch);
+
+        return json_decode($result);
+    }
+}
diff --git a/index.php b/index.php
deleted file mode 100644
index 75f11d6..0000000
--- a/index.php
+++ /dev/null
@@ -1,50 +0,0 @@
-<?php
-// https://github.com/bitcart/whmcs-plugin/blob/master/modules/gateways/bitcartcheckout.php
-// https://github.com/bitcart/bitcart-fossbilling/blob/master/Bitcart/Bitcart.php
-
-use App\Helpers\ExtensionHelper;
-
-public function BitCart_getConfig()
-    {
-        return [
-            [
-                'name' => 'bitcart_api_endpoint',
-                'friendlyName' => 'Bitcart domain name',
-                'type' => 'text',
-                'description' => 'Your Bitcart instance\'s Merchants API URL.',
-                'required' => true,
-            ],
-            [
-                'name' => 'bitcart_store',
-                'friendlyName' => 'Bitcart store id',
-                'type' => 'text',
-                'description' => 'Store ID of your Bitcart Store.',
-                'required' => true,
-            ],
-            [
-                'name'=>'bitcart_admin_url',
-                'friendlyName' => 'Admin URL',
-                'type' => 'text',
-                'description' => 'Your Bitcart instance\'s Admin Panel URL.',
-                'required' => true,
-            ],
-        ];
-    }
-
-public function Bitcart_pay($total, $products, $orderId) 
-{
-
-}
-
-protected function _generateForm($invoiceID)
-    {
-        $htmlOutput = '<button name = "bitcart-payment" class = "btn btn-success btn-sm" onclick = "showModal();return false;">Pay now</button>';
-        $htmlOutput .= '<script src="' . $this->config['admin_url'] . '/modal/bitcart.js" type="text/javascript"></script>';
-        $htmlOutput .= '<script type=\'text/javascript\'>';
-        $htmlOutput .= 'function showModal() {';
-        $htmlOutput .= 'bitcart.showInvoice(\'' . $invoiceID . '\');';
-        $htmlOutput .= '}
-                        </script>
-                        </form>';
-        return $htmlOutput;
-}