diff --git a/.env.sample b/.env.sample
index 076f629..f6f50f9 100644
--- a/.env.sample
+++ b/.env.sample
@@ -1,6 +1,6 @@
 # This environment file holds a dummy plugin from Freemius for testing purposes.
 # PLUGIN ID
-VITE_PLUGIN_ID=311
+VITE_PRODUCT_ID=311
 # PUBLIC KEY
 VITE_PUBLIC_KEY="pk_a42d2ee6de0b31c389d5d11e36211"
 # PLAN IDs
diff --git a/README.md b/README.md
index 8c3bf5c..662d95c 100644
--- a/README.md
+++ b/README.md
@@ -296,22 +296,41 @@ export default function App() {
 
 ## Testing with the Sandbox
 
-To get the sandbox token and ctx, follow the steps:
+This sample code uses PHP to generate the token and timestamp but you can 
+use the same approach in any server-side environment which will protect 
+the secret key.
 
 1. Go to the Developer Dashboard.
 2. Under Plans click on the "Get Checkout Code" button.
 3. Go to the Sandbox tab.
-4. Copy the `sandbox_token` and `timestamp` values.
+4. Copy the code to generate the `sandbox_token` and `timestamp` values and 
+output them for the Javascript to use.
+
+Example:
+
+```PHP
+<?php
+$plugin_id         = 1; // Change to your product ID
+$plugin_public_key = 'pk_00001'; // Your public key
+$plugin_secret_key = 'sk_00001'; // Your secret key
+$timestamp         = time();
+
+$sandbox_token = md5(
+    $timestamp .
+    $plugin_id .
+    $plugin_secret_key .
+    $plugin_public_key .
+    'checkout'
+);
+```
 
-The value of `sandbox` is token and value of `s_ctx_ts` is ctx. So for the above
-value, the configuration would look like
 
 ```js
 const config = {
     // ...
     sandbox: {
-        token: 'xxxxxxxx',
-        ctx: '00000000',
+        token: '<?php echo $sandbox_token; ?>',
+        ctx: '<?php echo $timestamp; ?>'
     },
 };
 ```
diff --git a/cypress/pages/common.ts b/cypress/pages/common.ts
index bd74ffa..c103ff5 100644
--- a/cypress/pages/common.ts
+++ b/cypress/pages/common.ts
@@ -1,8 +1,8 @@
 import { CheckoutOptions, CheckoutPopupEvents } from '../../src';
 
 export const initOptions: CheckoutOptions = {
-    plugin_id: Number.parseInt(
-        (import.meta.env.VITE_PLUGIN_ID as string) ?? '0',
+    product_id: Number.parseInt(
+        (import.meta.env.VITE_PRODUCT_ID as string) ?? '0',
         10
     ),
     public_key: import.meta.env.VITE_PUBLIC_KEY as string,
diff --git a/src/demo.ts b/src/demo.ts
index 798a2db..abd2676 100644
--- a/src/demo.ts
+++ b/src/demo.ts
@@ -4,8 +4,8 @@ import './style.css';
 
 const fsCheckout = new Checkout(
     {
-        plugin_id: Number.parseInt(
-            (import.meta.env.VITE_PLUGIN_ID as string) ?? '0',
+        product_id: Number.parseInt(
+            (import.meta.env.VITE_PRODUCT_ID as string) ?? '0',
             10
         ),
         public_key: import.meta.env.VITE_PUBLIC_KEY as string,