One of our client came up with a requirement where he adjusted payment type as authorize along with new orders to be placed as processing status.

Our work was to do execute cronjob such a way that it generates an invoice and capture the payment under technical limitation capped by client.

To execute the job we created a cronjob & set it at every minute.

Have a look on step-by-step explaination.

Step 1:  We create a crontab.xml in module at app/code/Magemonkeys/Generateinvoice/etc/crontab.xml and add the following code in the XML.

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Cron:etc/crontab.xsd">
    <group id="default">
        <job name="magemonkeys_generateinvoice_programmatically" instance="MagemonkeysGenerateinvoiceCronInvoicegenerate" method="execute">
            <schedule>* * * * *</schedule>
        </job>
    </group>
</config>

Step 2: Then, we create an Invoicegenerate.php at app/code/Magemonkeys/Generateinvoice/Cron/Invoicegenerate.php and add the following code in this file.

<?php

namespace MagemonkeysGenerateinvoiceCron;

use MagentoFrameworkExceptionLocalizedException;

class Invoicegenerate
{
    /**
     * @var MagentoSalesApiOrderRepositoryInterface 
     */
    private $_orderRepository;

    /**
     * @var MagentoSalesModelServiceInvoiceService 
     */
    private $_invoiceService;

    /**
     * @var MagentoFrameworkDBTransactionFactory 
     */
    private $_transactionFactory;

    /**
     * @var MagentoSalesModelOrderEmailSenderInvoiceSender 
     */
    private $_invoiceSender;

    /**
     * @var MagentoSalesModelResourceModelOrderCollectionFactory 
     */
    private $_orderCollectionFactory;

    public function __construct(
        MagentoSalesApiOrderRepositoryInterface $orderRepository,
        MagentoSalesModelServiceInvoiceService $invoiceService,
        MagentoFrameworkDBTransactionFactory $transactionFactory,
        MagentoSalesModelOrderEmailSenderInvoiceSender $invoiceSender,
        MagentoSalesModelResourceModelOrderCollectionFactory $orderCollectionFactory
    )
    {
        $this->_orderRepository = $orderRepository;
        $this->_invoiceService = $invoiceService;
        $this->_transactionFactory = $transactionFactory;
        $this->_invoiceSender = $invoiceSender;
        $this->_orderCollectionFactory = $orderCollectionFactory;
    } 

    public function execute()
    {

        $orderCollection = $this->_orderCollectionFactory->create()
            ->addAttributeToSelect('*')
            ->addFieldToFilter('status', 'processing');

        $objectManager = MagentoFrameworkAppObjectManager::getInstance();
        $logger = $objectManager->get("PsrLogLoggerInterface");
        
        foreach ($orderCollection as $order) {
            if($order->hasInvoices()) { 
                $logger->info('Order #'.$order->getId().' has already been invoiced.'); 
                continue;
            }

            
            $payment = $order->getPayment();
            $method = $payment->getMethodInstance();
            $methodTitle = $method->getTitle();
            if(strtolower($methodTitle) == 'credit card'){
                try {
                    
                    $order = $this->_orderRepository->get($order->getId());

                    if (!$order->getId()) {
                        $logger->info('Order #'.$order->getId().' no longer exists.'); 
                        continue;
                    }

                    if(!$order->canInvoice()) {
                        $logger->info('Order #'.$order->getId().' does not allow an invoice to be created.');
                        continue;
                    }

                    $invoice = $this->_invoiceService->prepareInvoice($order);
                    
                    if (!$invoice) {
                        $logger->info("Order #".$order->getId()." can't save the invoice right now.");
                        continue;
                    }
                    
                    if (!$invoice->getTotalQty()) {
                        $logger->info("Order #".$order->getId()." create an invoice without products.");
                        continue;
                    }

                    $invoice->setRequestedCaptureCase(MagentoSalesModelOrderInvoice::CAPTURE_ONLINE);
                    $invoice->register();
                    $invoice->getOrder()->setCustomerNoteNotify(false);
                    $invoice->getOrder()->setIsInProcess(true);
                    $order->addStatusHistoryComment('Automatically INVOICED', false);
                    $transactionSave = $this->_transactionFactory->create()->addObject($invoice)->addObject($invoice->getOrder());
                    $transactionSave->save();

                    // send invoice emails
                    try {
                        $this->_invoiceSender->send($invoice);
                        $logger->info("Order #".$order->getId()." - Invoice has been created successfully.");
                    } catch (Exception $e) {
                        $logger->info("Order #".$order->getId()." - We can't send the invoice email right now.");
                    }
                } catch (Exception $e) {
                    
                   $logger->info($e->getMessage());
                }
            }
        }
    }
}