PayPal Payments - HTTP Response code 400 - php

Question

I'm workin on PayPal Payments in PHP. Everything was fine until i got this error:
Got Http response code 400 when accessing https://api.sandbox.paypal.com/v1/payments/payment.
It's thrown when I try to create method for my payment: $payment->create($api);
<?php
use PayPal\Api\Payer;
use PayPal\Api\Details;
use PayPal\Api\Amount;
use PayPal\Api\Transaction;
use PayPal\Api\Payment;
use PayPal\Api\RedirectUrls;
use PayPal\Exception\PayPalConnectionException;
require '../src/start.php';
$payer = new Payer();
$details = new Details();
$amount = new Amount();
$transaction = new Transaction();
$payment = new Payment();
$redirectUrls = new RedirectUrls();
// Payer
$payer->setPaymentMethod('paypal');
// Details
$details->setShipping('2.00')
->setTax('0.00')
->setSubtotal('20.00');
// Amount
$amount->setCurrency('GBP')
->setTotal('22.00')
->setDetails($details);
// Transaction
$transaction->setAmount($amount)
->setDescription('Membership');
// Payment
$payment->setIntent('sale')
->setPayer($payer)
->setTransactions($transaction);
// Redirect urls
$redirectUrls->setReturnUrl($myReturnUrl)
->setCancelUrl($myCancelUrl);
$payment->setRedirectUrls($redirectUrls);
try {
$payment->create($api);
} catch (Exception $e) {
echo $e->getMessage();
}
Why this is happening? How can I fix that? How eventually I can get more detailed exception message?

Answer 1

// Amount
$amount->setCurrency('GBP')
->setTotal('22.00')
->setDetails($details);
And make sure also your paypal business account whats your primary currency in my case it worked fine with changing the value from 'GBP' to 'USA'
// Amount
$amount->setCurrency('USA')
->setTotal('22.00')
->setDetails($details);

Answer 2

$api = new \PayPal\Rest\ApiContext(
new \PayPal\Auth\OAuthTokenCredential('Your Client ID',' Secret')
);
Make sure you have provided that right values