Zend certified PHP/Magento developer

How to display a message when unset a shipping method in magento 2.3 using aroundEstimateByExtendedAddress plugin?

Want to display a message after certain conditions, how to achieve that?

class ShipmentEstimationPlugin
{
    public function __construct(
        MagentoCustomerModelSession $customerSession

    ) {
        $this->customerSession = $customerSession;

    }

    public function aroundEstimateByExtendedAddress(
        ShipmentEstimationInterface $subject,
        Closure $proceed,
        $cartId,
        MagentoQuoteApiDataAddressInterface $address
    ) {
        $writer = new ZendLogWriterStream(BP . '/var/log/testshipping.log');
        $logger = new ZendLogLogger();
        $logger->addWriter($writer);


       $objectManager = MagentoFrameworkAppObjectManager::getInstance();
       $cart = $objectManager->get('MagentoCheckoutModelCart'); 
       $itemsCollection = $cart->getQuote()->getItemsCollection();
       $itemsVisible = $cart->getQuote()->getAllVisibleItems();
       $items = $cart->getQuote()->getAllItems();
       $product = $objectManager->create('MagentoCatalogModelProduct');

       $brands =  array();
       foreach($items as $item) {
        $loaded_product = $product->load($item->getProductId());
        $product = $product->load($item->getProductId());
        $brand = null;
        $brand=$loaded_product->getResource()->getAttribute('brand')->getFrontend()->getValue($loaded_product);
        $brand = strval($brand);
        $subTotal = $cart->getQuote()->getSubtotal();
        // $items = array($brand);
        array_push($brands, $brand);

        }


        $size = sizeof($brands);
        $logger->info($brands);
        $logger->info($size);
        $pelican = in_array("Pelican",$brands);
        $nanuk = in_array("Nanuk", $brands);
        $other = in_array("Other", $brands);


        $logger->info("Pelican");
        $logger->info($pelican);
        $logger->info("Nanuk");
        $logger->info($nanuk);
        $logger->info("Other");
        $logger->info($other);


        $code=$address->getPostcode();
        $region=$address->getRegionId();
        $logger->info($code);
        $logger->info($region);

        $check = stripos($code, '0') === 1;
        $logger->info(stripos($code, '0') === 1);



        $shippingMethods = $proceed($cartId, $address);

        if ($code) { 
            if ($check ) { 
                foreach ($shippingMethods as $key => $shippingMethod) {
                    if($shippingMethod->getMethodCode() == "freeshipping"){
                        unset($shippingMethods[$key]);
                    }        
                }
            }
        }

        if ($region) { // Check is regionid exists in request
            $regionid = $region;
            if ($regionid == 69 || $regionid == 72 || $regionid == 73 || $regionid == 75 || $regionid == 78) { 
                foreach ($shippingMethods as $key => $shippingMethod) {
                    if($shippingMethod->getMethodCode() == "freeshipping"){
                        unset($shippingMethods[$key]);
                    }        
                }
            }
        }

        if( in_array("Pelican",$brands) || in_array("Nanuk",$brands)){
            if($subTotal >= 150){    
                if( in_array("Other", $brands) || in_array("SKB", $brands)) 
                {            
                 if ($regionid == 69 || $regionid == 72 || $regionid == 73 || $regionid == 75 || $regionid == 78 || $check) {                                                                                                           foreach ($shippingMethods as $key => $shippingMethod) {
                            if($shippingMethod->getMethodCode() == "freeshipping"){
                              unset($shippingMethods[$key]);
                            }        
                        }
                        $logger->info("Pelican & Non Pelican found");
                        $logger->info("You are not eligible for free shipping");

                    }
                    else
                    {

                    foreach ($shippingMethods as $key => $shippingMethod) {
                        if($shippingMethod->getMethodCode() == "freeshipping"){
                            unset($shippingMethods[$key]);
                        }        
                    }
                    $logger->info("Pelican & Non Pelican found");
                    $logger->info("You may be eligible for free shipping");

//not Working 
 $question = $objectManager->create('MagentoFrameworkMessageManagerInterface');
                    $question->addWarning(__("Warning"));
//not working
                     //Want to display message here 
                    // echo "You may be eligible for free shipping. Contact at websales@productioncase.com for you free quote";


                    }

                }
                else
                {
                    $logger->info("Only Pelican/Nanuk found");
                }            
            }else{
                foreach ($shippingMethods as $key => $shippingMethod) {
                    if($shippingMethod->getMethodCode() == "freeshipping"){
                        unset($shippingMethods[$key]);
                    }        
                }
            }
        }
        else {   
            foreach ($shippingMethods as $key => $shippingMethod) {
                if($shippingMethod->getMethodCode() == "freeshipping"){
                    unset($shippingMethods[$key]);
                }        
            }
        }

    return $shippingMethods;

    }

}