PayPalPaymentServiceV1.java

@Service
public class PayPayPaymentService implements PaymentService{

    private final PayPalHttpClient payPalHttpClient;

    public PayPayPaymentService(@Value("${paypal.clientId}") String clientId,
                                @Value("${paypal.clientSecret}") String clientSecret) {
        payPalHttpClient = new PayPalHttpClient(new PayPalEnvironment.Sandbox(clientId, clientSecret));
    }

    @Override
    public CreatedOrder createOrder(Double totalAmount, URI returnUrl) {
        return null;
    }
}