title: Create an invoice for stripe payments
body: <p>I'm using Stripe for one-time payments and subscriptions.<br />
  To create a payment, I use Stripe Checkout:</p>
  <pre><code>\Stripe\Checkout\Session::create([
      'customer' =&gt; 'cus_XXXXX',
      'success_url' =&gt; '',
      'cancel_url' =&gt; '',
      'payment_method_types' =&gt; ['card'],
      'mode' =&gt; ($isSubscription ? 'subscription' : 'payment'),
      'line_items' =&gt; [...]
  ]);
  
  header('Location: '.$checkout_session-&gt;url);
  exit;
  </code></pre>
  <p>This code automatically create an invoice for subscription mode but not for one-time payments.<br />
  I've tried this to create a new invoice but how can I do to make it related to previous payment, closed and paid?</p>
  <pre><code>$stripe = new Stripe\StripeClient('xxx');
  $stripe-&gt;invoiceItems-&gt;create([
      'customer' =&gt; 'cus_XXXXX',
      'amount' =&gt; '1000',
      'currency' =&gt; 'eur',
      'description' =&gt; 'Lorem ipsum...'
  ]);
  $invoice = $stripe-&gt;invoices-&gt;create([
      'customer' =&gt; 'cus_XXXXX',
  ]);
  </code></pre>