An order represents a payment between two or more parties. and inorder to create a new order we must send an OrderCreateRequest to PayPal API.
use PayPal\Checkout\Requests\OrderCreateRequest;
use PayPal\Checkout\Orders\AmountBreakdown;
use PayPal\Checkout\Orders\Item;
use PayPal\Checkout\Orders\Order;
use PayPal\Checkout\Orders\PurchaseUnit;
// Create a purchase unit with the total amount
$purchase_unit = new PurchaseUnit(AmountBreakdown::of('200.00', 'USD'));
// Create & add item to purchase unit
$purchase_unit->addItem(Item::make('Item 1', '100.00', 'USD', 1));
$purchase_unit->addItem(Item::make('Item 2', '100.00', 'USD', 1));
// Create a new order with intent to capture a payment
$order = (new Order())->addPurchaseUnit($purchase_unit);
// Send request to PayPal
$response = $client->send(new OrderCreateRequest($order));
// Get results
$result = json_decode($response->getBody()->getContents());
A successful request returns the HTTP 201 Created status code and a JSON response body that includes by default a minimal response with the ID, status, and HATEOAS links.