If you want get query string params in controller file, then you can try like below.

<?php
namespace MageMonkeyCheckReqControllerIndex;

use MagentoFrameworkControllerResultFactory;
use MagentoFrameworkAppActionContext;
use MagentoFrameworkViewResultPageFactory;
 
class Index extends MagentoFrameworkAppActionAction
{
     protected $resultPageFactory;
    
    public function __construct(
        Context $context,
        PageFactory $resultPageFactory
    ) {
    
        parent::__construct($context);
        $this->resultPageFactory = $resultPageFactory;
    }
    
    public function execute()
    {	
        $params = $this->getRequest()->getParams();
        /* print_r($params); die */
        $this->_view->loadLayout();        
        $this->_view->getLayout()->initMessages();
        $this->_view->renderLayout();
    }
}