diff --git a/Writerside/hi.tree b/Writerside/hi.tree
index 70771b5..b2649b3 100644
--- a/Writerside/hi.tree
+++ b/Writerside/hi.tree
@@ -262,6 +262,8 @@
         <toc-element topic="Magento.md"/>
     </toc-element>
     <toc-element topic="API-Interaction.md">
-        <toc-element topic="API-Interaction-PHP.md"/>
+        <toc-element topic="API-Interaction-PHP.md">
+            <toc-element topic="Get-info-on-non-activated-invoices.md"/>
+        </toc-element>
     </toc-element>
 </instance-profile>
\ No newline at end of file
diff --git a/Writerside/topics/API-Interaction-PHP.md b/Writerside/topics/API-Interaction-PHP.md
index 991c19d..0e761c8 100644
--- a/Writerside/topics/API-Interaction-PHP.md
+++ b/Writerside/topics/API-Interaction-PHP.md
@@ -1,3 +1,5 @@
 # PHP
 
-Start typing here...
\ No newline at end of file
+Here you will find examples of how to interact with the Qvickly APIs using PHP.
+
+The examples are simple and could be used as a starting point for your own implementation.
diff --git a/Writerside/topics/Get-info-on-non-activated-invoices.md b/Writerside/topics/Get-info-on-non-activated-invoices.md
new file mode 100644
index 0000000..365ab4b
--- /dev/null
+++ b/Writerside/topics/Get-info-on-non-activated-invoices.md
@@ -0,0 +1,43 @@
+# Get info on non-activated invoices
+
+In this example we will authenticate against the Auth API, fetch a list of invoices from the Portal API and then use the Payment API to get more information about the invoices.
+
+The invoices we are looking for are invoices that are created, but not yet activated. We will use the `status`, `search` and `invoiceType` filters to find the invoices we are looking for. The number of invoices we want to fetch is limited to 5.
+
+<code-block lang="php">
+<![CDATA[
+<?php
+declare(strict_types=1);
+
+require __DIR__ . '/../../vendor/autoload.php';
+
+use Dotenv\Dotenv;
+use Qvickly\Api\Auth\AuthAPI;
+use Qvickly\Api\Portal\PortalAPI;
+use Qvickly\Api\Payment\PaymentAPI;
+
+
+$dotenv = Dotenv::createImmutable(__DIR__ . '/../..');
+$dotenv->load();
+
+$authAPI = new AuthAPI();
+$auth = $authAPI->login($_ENV['USERNAME'], $_ENV['PASSWORD']);
+
+$portalAPI = new PortalAPI($auth);
+
+$paymentAPI = new PaymentAPI($_ENV['EID'], $_ENV['SECRET']);
+
+$invoices = $portalAPI->get('invoices?filter=status,search,invoiceType&status=created&search=tess&invoicetype=F&limit=5');
+
+echo "Found " . count($invoices) . " invoices to activate.\n";
+
+foreach($invoices as $invoice) {
+    echo "Fetching invoice {$invoice['invoiceid_real']}...\n";
+    $payment = $paymentAPI->getPaymentInfo([ 'number' => $invoice['invoiceid_real']]);
+    echo json_encode($payment, JSON_PRETTY_PRINT) . "\n\n";
+}
+]]>
+</code-block>
+
+<include from="Snippets-PHP-Module.md" element-id="snippet-composer-require" />
+
diff --git a/Writerside/topics/initCheckout.md b/Writerside/topics/initCheckout.md
index ccb7e88..e231eb3 100644
--- a/Writerside/topics/initCheckout.md
+++ b/Writerside/topics/initCheckout.md
@@ -24,7 +24,7 @@ credentials
 data
 function
 
-#### checkoutdata
+#### CheckoutData
 | Property             | Required | Type    | Description                                                                       |
 |----------------------|----------|---------|-----------------------------------------------------------------------------------|
 | terms                | false    | string  | Url to the terms and conditions page for the store.                               |
@@ -107,7 +107,7 @@ function
         "test": "true"
     },
     "data": {
-        "checkoutdata":{
+        "CheckoutData":{
           "terms": "http://qvickly.io/terms",
           "privacyPolicy": "http://qvickly.io/privacy-policy",
           "companyview": "false",
diff --git a/Writerside/topics/isPaid.md b/Writerside/topics/isPaid.md
index 30f5b99..4dd80c4 100644
--- a/Writerside/topics/isPaid.md
+++ b/Writerside/topics/isPaid.md
@@ -11,10 +11,15 @@ return by echo JSON string.
 
 {type="narrow"}
 Endpoint
-: /ajax.php?isPaid
+: /public/ajax.php?isPaid
 
 Method
-: GET
+: POST
+
+## Request
+
+| Property | Type   | Description |
+|----------|--------|-------------|
 
 ## Repsonse