Step 1: create a “Registration.php” file inside our extension at the following path.

Path: appcodeMagemonkeysRemovecart

<?php
MagentoFrameworkComponentComponentRegistrar::register(
    MagentoFrameworkComponentComponentRegistrar::MODULE,
    'Magemonkeys_Removecart',
    __DIR__
);

Step 2: After that,  create a “Module.xml” file inside extension etc folder. appcodeMagemonkeysRemovecartetc

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
    <module name="Magemonkeys_Removecart" setup_version="1.0.0" schema_version="1.0.0">
    </module>
</config>

Step 3: After that, create “crontab.xml” file inside extension etc folder. appcodeMagemonkeysRemovecartetc

<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="removecart" instance="MagemonkeysRemovecartCronRemovecart" method="getItemData">
            <schedule>* * * * *</schedule>
        </job>
    </group>
</config>

Step 4: Lastly, Create the “Removecart.php” file inside the Cron folder of extension. appcodeMagemonkeysRemovecartCron

<?php
namespace MagemonkeysRemovecartCron;

class Removecart {

    /**
     * @var MagentoQuoteModelQuoteRepository
     */
    protected $quoteRepository;

    /**
     * @var MagentoQuoteModelResourceModelQuoteCollectionFactory
     */
    protected $quoteCollectionFactory;

    public function __construct(
        MagentoQuoteModelResourceModelQuoteCollectionFactory $quoteCollectionFactory,
        MagentoQuoteModelQuoteRepository $quoteRepository
    ) {

        $this->quoteCollectionFactory = $quoteCollectionFactory;
        $this->quoteRepository = $quoteRepository;
    }
    public function getItemData()
    {
        $fromTime = new DateTime('now', new DateTimezone('UTC'));
        $fromTime->sub(DateInterval::createFromDateString('30 minutes'));

        $fromDate = $fromTime->format('Y-m-d H:i:s');
        $quoteCollection = $this->quoteCollectionFactory->create();

        $quoteCollection
            ->addFieldToFilter('created_at', ['lteq' => $fromDate]);

        if($quoteCollection->getSize() >0){
            foreach ($quoteCollection as $quote)
            {
                $quoteFullObject = $this->quoteRepository->get($quote->getId());
                $quoteFullObject->delete();
            }
        }


    }
}

Run below command in your command prompt

php bin/magento cron:install

php bin/magento cron:run

Every 30 minutes, the cron is executed. If there is an item available in the cart, it will be then removed, automatically!