Paypal Sandbox link is not working - https://www.sandbox.paypal.com/cgi-bin/webscr

[guptavijay208]

I am trying to integrate paypal for one time donation save data to database and then mark paid/unpaid using Paypal IPN, I was working with below code yesterday, it was working fine and was redirecting me to sandbox page to pay and then come back.

below is my php form

<form method="post" action="<?php echo base_url(); ?>controller/function" name="DonationForm" id="DonationForm" class="mt-20">
 <input type="number" min="1" placeholder="Amount" id="amount" name="amount" class="form-control">

<!------ here i have some more variables to insert in database-->
</form>

 and below is my codeigniter function

$UniqueIdGenrated=md5(uniqid(mt_rand(), FALSE));
$UniqueId=$UniqueIdGenrated;
$paypal_email = 'my_sandbox_bussiness_email[at]gmail.com';$return_url = 'https://my_domain.com/controller/payment-successful';
$cancel_url = 'https://my_domain.com/controller/payment-cancelled';$notify_url = 'https://my_domain.com/paypal/listener.php';$currency_code='USD';
$item_name='Donation for a cause';
$item_number=$UniqueId;
$amount=$_POST['amount'];$cmd='_xclick';
//$lc='UK';
//$bn='PP-BuyNowBF:btn_buynow_LG.gif:NonHostedGuest';$querystring = '';
$querystring .= "?business=".urlencode($paypal_email)."&";
$querystring .= "item_name=".urlencode($item_name)."&";
$querystring .= "amount=".urlencode($amount)."&";
$querystring .= "item_number=".urlencode($item_number)."&";
$querystring .= "currency_code=".urlencode($currency_code)."&";
$querystring .= "cmd=".urlencode($cmd)."&";

// Append paypal return addresses
$querystring .= "return=".urlencode(stripslashes($return_url))."&";
$querystring .= "cancel_return=".urlencode(stripslashes($cancel_url))."&";
$querystring .= "notify_url=".urlencode($notify_url);
header('location:https://www.sandbox.paypal.com/cgi-bin/webscr'.$querystring);
exit();

However today when I started testing again, paypal says "Things don't appear to be working at the moment. Please try again later."

I tried keeping below as header, live paypal

header('location:https://www.paypal.com/cgi-bin/webscr'.$querystring);

then it has taken me properly on paypal payment page below is the screen shot

Can anyone please help me, am i missing something 😞