Uncaught PPConnectionException Http response code 400

[nodirtyrockstar]

Basically what I can see is that I am failing to create the apiContext object. Can anyone see where the error is? Please tell me how I can improve the question.
 

Here is the error:
 

Fatal error: Uncaught exception 'PayPal\Exception\PPConnectionException' with message 'Got Http response code 400 when accessing https://api.sandbox.paypal.com/v1/payments/payment.' in /vendor/paypal/sdk-core-php/lib/PayPal/Core/PPHttpConnection.php:104 Stack trace: #0 /vendor/paypal/sdk-core-php/lib/PayPal/Transport/PPRestCall.php(44): PayPal\Core\PPHttpConnection->execute('{"intent":"sale...') #1 /vendor/paypal/rest-api-sdk-php/lib/PayPal/Api/Payment.php(246): PayPal\Transport\PPRestCall->execute(Array, '/v1/payments/pa...', 'POST', '{"intent":"sale...') #2 /pymt.php(38): PayPal\Api\Payment->create(Object(PayPal\Rest\ApiContext)) #3 {main} thrown in /vendor/paypal/sdk-core-php/lib/PayPal/Core/PPHttpConnection.php on line 104
 

This is the PHP sample I'm using. I am trying to run it off my server. If a customer clicks the pay with paypal button, it runs the following sample script:

<?php

require __DIR__ . '/../bootstrap.php';
use PayPal\Api\Address;
use PayPal\Api\Amount;
use PayPal\Api\Payer;
use PayPal\Api\Payment;
use PayPal\Api\FundingInstrument;
use PayPal\Api\RedirectUrls;
use PayPal\Api\Transaction;
session_start();



$payer = new Payer();
$payer->setPayment_method('paypal');

$amount = new Amount();
$amount->setCurrency('USD');
$amount->setTotal('1.00');

$transaction = new Transaction();
$transaction->setAmount($amount);
$transaction->setDescription('This is the payment description.');

$baseUrl = getBaseUrl();
$redirectUrls = new RedirectUrls();
$redirectUrls->setReturn_url('baseUrl/sale.php');
$redirectUrls->setCancel_url('baseUrl/saleFail.php');

$payment = new Payment();
$payment->setIntent('sale');
$payment->setPayer($payer);
$payment->setRedirect_urls($redirectUrls);
$payment->setTransactions(array($transaction));

try {
$payment->create($apiContext);
} catch (\PPConnectionException $ex) {
echo 'Exception: ' . $ex->getMessage() . PHP_EOL;
var_dump($ex->getData());
exit(1);
}

foreach ($payment->getLinks() as $link) {
if ($link->getRel() == 'approval_url') {
$redirectUrl = $link->getHref();
}
}

$_SESSION['paymentId'] = $payment->getId();
if(isset($redirectUrl)) {
header('Location: $redirectUrl');
exit;
}
?>

Here's the redacted bootstrap.php:

<?php

/*
* Sample bootstrap file.
*/

// Include the composer autoloader
if(!file_exists(__DIR__ .'/vendor/autoload.php')) {
echo "The 'vendor' folder is missing. You must run 'composer update --no-dev' to resolve application dependencies.\nPlease see the README for more information.\n";
exit(1);
}


require __DIR__ . '/vendor/autoload.php';
require __DIR__ . '/common.php';

use PayPal\Rest\ApiContext;
use PayPal\Auth\OAuthTokenCredential;

$apiContext = getApiContext();

/**
Helper method for getting an APIContext for all calls
*
* @return PayPal\Rest\ApiContext
*/
function getApiContext() {

// ### Api context
// Use an ApiContext object to authenticate 
// API calls. The clientId and clientSecret for the 
// OAuthTokenCredential class can be retrieved from 
// developer.paypal.com

$apiContext = new ApiContext(
new OAuthTokenCredential(
'MY CLIENT ID',
'MY SECRET'
)
);


// Register the sdk_config.ini file in current directory
// as the configuration source.
if(!defined("PP_CONFIG_PATH")) {
define("PP_CONFIG_PATH", __DIR__);
}

return $apiContext;
}
?>

Can anyone help? Let me know if you need more info. Thanks up front.