How can you add a size option to Stripe Custom Checkout? As of right now I have this for using the custom checkout with a script tag.
<?php
require('config.php');
?>
<form action="charge.php" method="post">
<script src="https://checkout.stripe.com/checkout.js" class="stripe-button"
data-key="<?php echo $stripe['publishable_key']?>"
data-amount="3500"
data-locale="auto"
data-company="Company Name"
data-billingAddress="true"
data-email="true">
</script>
</form>