<form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post" name="frmTransaction" id="frmTransaction">
    <input type="hidden" name="business" value="{{$paypal_id}}">
    <input type="hidden" name="cmd" value="_xclick">
     <input type="hidden" name="item_name" value="{{$product->name}}">
    <input type="hidden" name="item_number" value="{{$product->id}}">
    <input type="hidden" name="amount" value="{{$product->price}}">
    <input type="hidden" name="currency_code" value="USD">
    <input type="hidden" name="cancel_return" value="http://blog-gan.org/payment-cancel">
    <input type="hidden" name="return" value="http://blog-gan.org/payment-status">
</form>
<SCRIPT>document.frmTransaction.submit();</SCRIPT>