<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Framework\App\RouterList">
        <arguments>
            <argument name="routerList" xsi:type="array">
                <item name="customRoute" xsi:type="array">
                    <item name="class" xsi:type="string">Mage2\CustomRouter\Controller\Router</item>
                    <item name="disable" xsi:type="boolean">false</item>
                    <item name="sortOrder" xsi:type="string">31</item>
                </item>
            </argument>
        </arguments>
    </type>
</config>

after that, we need to create Router.php.
Controller/Router.php

<?php

declare(strict_types=1);

namespace Mage2\CustomRouter\Controller;

use Magento\Framework\App\Action\Forward;
use Magento\Framework\App\ActionFactory;
use Magento\Framework\App\ActionInterface;
use Magento\Framework\App\RequestInterface;
use Magento\Framework\App\ResponseInterface;
use Magento\Framework\App\RouterInterface;

/**
 * Class Router for create custom route for parts
 */
class Router implements RouterInterface
{
    /**
     * @var ActionFactory
     */
    private $actionFactory;

    /**
     * @var ResponseInterface
     */
    private $response;

    /**
     * @param ActionFactory $actionFactory
     * @param ResponseInterface $response
     */
    public function __construct(
        ActionFactory     $actionFactory,
        ResponseInterface $response
    ) {
        $this->actionFactory = $actionFactory;
        $this->response = $response;
    }

    /**
     * Class matching routing path and setting custom route
     *
     * @param RequestInterface $request
     * @return ActionInterface|null
     */
    public function match(RequestInterface $request): ?ActionInterface
    {
        $identifier = trim($request->getPathInfo(), '/');

        if (strpos($identifier, 'custompath') !== false) {
            $request->setModuleName('learning');
            $request->setControllerName('index');
            $request->setActionName('index');
            $request->setParams([
                                    'custom_param' => 'custom_value'
                                ]);

            return $this->actionFactory->create(Forward::class, ['request' => $request]);
        }

       return null;
    }
}

Here, in the Router.php file line 51 we are checking if Urlindetifier getting custompath setting learning_index_index layout handle.
Now we need to create a routes.xml file for defining route learning

etc/frontend/routes.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
    <router id="standard">
        <route id="learning" frontName="learning">
            <module name="Mage2_CustomRouter"/>
        </route>
    </router>
</config>

Need to create a controller file for the learning route.
Controller/Index/Index.php

<?php

declare(strict_types=1);

namespace Mage2\CustomRouter\Controller\Index;

use Magento\Framework\App\Action\HttpGetActionInterface;
use Magento\Framework\App\RequestInterface;
use Magento\Framework\View\Result\Page;
use Magento\Framework\View\Result\PageFactory;

/**
 * Catalog index page controller.
 */
class Index implements HttpGetActionInterface
{
    /**
     * @var PageFactory
     */
    private $pageFactory;

    /**
     * @param PageFactory $pageFactory
     * @param RequestInterface $request
     */
    public function __construct(
        PageFactory      $pageFactory,
        RequestInterface $request
    ) {
        $this->pageFactory = $pageFactory;
        $this->request = $request;
    }

    /**
     * Return Part page
     *
     * @return Page
     */
    public function execute(): Page
    {
        // Get the params that were passed from our Router
        $resultPage = $this->pageFactory->create();
        $customParam = $this->request->getParam('custom_param', null);

        return $resultPage;
    }
}

Now we need to create a layout file for that layout handle learning_index_index
view/frontend/layout/learning_index_index.xml

<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
    <body>
        <referenceBlock name="page.main.title">
            <action method="setPageTitle">
                <argument translate="true" name="title" xsi:type="string">Custom Routing Page</argument>
            </action>
        </referenceBlock>
    </body>
</page>

Now you can access https://”your.domain.com”/custompath/
it will be showing the same as https://”your.domain.com”/learning/index/index