Omnipay Paypal set store name and logo (Laravel) - paypal

Question

How can I set the store name and logo using the Omnipay Paypal package for Laravel?
Please see my code below, until now I tried to use the method setBrandName on the gateway variable, but this method was not found. It seems like the class ExpressCheckout has such methods but is like deprecated and one should use this code and checkout procedure. Also tried to add entry to the purchase method array parameter but it didn't work.
<?php
namespace App\Http\Controllers;
..
use Omnipay\Omnipay;
class PurchaseController extends Controller
{
public $gateway;
public function __construct()
{
$this->gateway = Omnipay::create('PayPal_Rest');
$this->gateway->setClientId(...);
$this->gateway->setSecret(...);
$this->gateway->setTestMode(true);
}
protected function makePurchase(Request $request) {
try {
$items = ...;
$response = $this->gateway->purchase(array(
'amount' => $cart->getSum(),
'items' => $items,
'currency' => config('paypal.currency'),
'returnUrl' => route('payment.success'),
'cancelUrl' => route('cart'),
))->send();
if ($response->isRedirect()) {
$response->redirect(); // this will automatically forward the customer
} else {
// not successful
return $response->getMessage() . ", " . $response->getCode();
}
} catch(Exception $e) {
return $e->getMessage();
}
}
protected function purchaseCompleted(Request $request) {
...
}
}