Kdjykuj

    try {

            $store=$this->_storeManager->getStore();

            $websiteId = $this->_storeManager->getStore()->getWebsiteId();

            $customer=$this->customerFactory->create();

            $customer->setWebsiteId($websiteId);

            $customer->loadByEmail($firstOrderDetails->getCustomerEmail());// load customet by email address



            if (!$customer->getEntityId()) {

                //If not avilable then create this customer

                $customer->setWebsiteId($websiteId)

                ->setStore($store)

                ->setFirstname($firstOrderDetails->getShippingAddress()->getData('firstname'))

                ->setLastname($firstOrderDetails->getShippingAddress()->getData('lastname'))

                ->setEmail($firstOrderDetails->getCustomerEmail())

                ->setPassword($firstOrderDetails->getCustomerEmail());

                $customer->save();

            }

            //init the quote

            $cart_id = $this->cartManagementInterface->createEmptyCart();

            $cart = $this->cartRepositoryInterface->get($cart_id);

            $cart->setStore($store);





            // if you have allready buyer id then you can load customer directly

            $customer= $this->customerRepository->getById($customer->getEntityId());

            $cart->setCurrency();

            $cart->assignCustomer($customer); //Assign quote to customer



            //add items in quote

            foreach ($orderAllItems as $item) {

                $product = $this->_product->load($item['Product_id']);

                $params = array('product' => $item['Product_id'], 'qty' => $item['Qty'],'form_key' => $this->_formkey->getFormKey());

                $cart->addProduct(

                    $product,

                    $params

                );

            }



            //Set Address to quote

            $cart->getBillingAddress()->addData($firstOrderDetails->getBillingAddress()->getData());

            $cart->getShippingAddress()->addData($firstOrderDetails->getShippingAddress()->getData());



            // Collect Rates and Set Shipping & Payment Method



            $shippingAddress=$cart->getShippingAddress();

            $shippingAddress->setCollectShippingRates(true)

                        ->collectShippingRates()

                        ->setShippingMethod($firstOrderDetails->getShippingMethod()); //shipping method

            $cart->setPaymentMethod($firstOrderDetails->getPayment()->getMethodInstance()->getCode()); //payment method

            $cart->setInventoryProcessed(false); //not effetc inventory





            // Set Sales Order Payment

            $cart->getPayment()->importData(['method' => $firstOrderDetails->getPayment()->getMethodInstance()->getCode()]);



            // Collect Totals & Save Quote

            $cart->collectTotals()->save();



            // Create Order From Quote

            $cart = $this->cartRepositoryInterface->get($cart->getId());



            $cart->setTotalsCollectedFlag(true)->collectTotals();

            $cart->collectTotals()->save();





            $order_id = $this->cartManagementInterface->placeOrder($cart->getId());

            if (isset($order_id) && !empty($order_id)) {

                $result["success"] = $order_id;

            }

        } catch (Exception $e) {

            print_r($e->getMessage());

            exit("123");

        }

    }