How to send each individual products Id of Grouped Products in Magento 2?

I need to be sent the individual product IDs of Grouped Products.

By default, Magento sends a grouped product ID for all individual products.

Here, how to get individual product IDs of Grouped Products.

Helper Class:

public function getProductDatalayer($productId, $simpleProductId = null)
{
    $productData = array();

    $product = $this->_productRepository->getById($productId);
    $productDefault = $this->_productRepository->getById($productId, false, self::DEFAULT_STORE_ID);
    $objectManager = MagentoFrameworkAppObjectManager::getInstance();
    $imageHelper = $objectManager->get(MagentoCatalogHelperImage::class);
    $imageUrl = $imageHelper->init($product, 'product_base_image')->getUrl();

    $simpleProdData = $this->getSimpleProductsSize($product);

    $productData['id']       = $product->getId();
    // $productData['product_id'] = 
    $size = !empty($size) ? $size : $simpleProdData['size'];
    
    $productData['product_id'] = $this->getProductIdBySize($product, $size);


    $writer = new Zend_Log_Writer_Stream(BP . '/var/log/test77777log');
    $logger = new Zend_Log();
    $logger->addWriter($writer);
    $logger->info($productData['product_id']);
    $logger->info($size);



    $productData['name']     = $productDefault->getName();
    $productData['price']    = $product->getPriceInfo()->getPrice('regular_price')->getValue();
    $productData['brand']    = $productDefault->getResource()->getAttribute('tommy_label')->setStoreId(self::DEFAULT_STORE_ID)->getFrontend()->getValue($productDefault);
    $productData['category'] = $this->getProductCategory($productDefault);

    $productData['category_id'] = $this->getProductCategoryIds($productDefault);
    $productData['variant']  = $productDefault->getResource()->getAttribute('color')->setStoreId(self::DEFAULT_STORE_ID)->getFrontend()->getValue($productDefault);
    $productData['sale_status']  = ($this->getProductDiscountPercent($product) > 0) ? 'On Offer' : 'No Offer';
    $productData['stock_status'] = ($product->isInStock() == 1) ? 'In Stock' : 'Out of Stock';
    $productData['discount_percent'] = $this->getProductDiscountPercent($product);
    $productData['product_image'] =$imageUrl;
    $productData['discount_price'] = $product->getFinalPrice();
    $productData['product_gender'] = $productDefault->getResource()->getAttribute('gender')->setStoreId(self::DEFAULT_STORE_ID)->getFrontend()->getValue($productDefault);

    return $productData;
}

Ajax:

public function execute()
{

    $requestParams = $this->getRequest()->getParams();

    $items = array();

    $productId = isset($requestParams['product']) ? (int)$requestParams['product'] : null;
    $simple_productId = isset($requestParams['simple_product_id']) ? (int)$requestParams['simple_product_id'] : null;

    try {

        if (!$productId) {
        
            $response = array(
                'errors' => true,
                'message' => 'Product not found.'
            );
        
        } else {

            $items = $this->helper->getProductDatalayer($productId, $simple_productId); 

            if( isset($requestParams['event']) ) {

                $datalayer_flow = array();
                $datalayer_flow = $this->checkoutSession->getDatalayerFlow();

                if( $requestParams['event'] == 'Add_To_Cart' ) {

                    $items['quantity'] = 1;
                    $items['size'] = $requestParams['size'];
                    $items['buy_flow'] = 'Normal Flow';

                    //flow handle
                    $datalayer_flow[$productId] = array(
                        'buy_flow' => 'Normal Flow'
                    );
                    //$this->checkoutSession->setDatalayerFlow($datalayer_flow);

                } elseif ( $requestParams['event'] == 'Quickbuy_Add_To_Cart' ) {
                    
                    $items['quantity'] = 1;
                    $items['size'] = $requestParams['size'];
                    $items['buy_flow'] = 'Quick Buy';

                    //flow handle
                    $datalayer_flow[$productId] = array(
                        'buy_flow' => 'Quick Buy'
                    );
                    //$this->checkoutSession->setDatalayerFlow($datalayer_flow);

                } elseif ( $requestParams['event'] == 'productClick' ) {

                    $items['position'] = $requestParams['position'];
                    $datalayer_flow[$productId] = array(
                        'list' => $requestParams['list']
                    );

                }

                $this->checkoutSession->setDatalayerFlow($datalayer_flow);
            }

            $response = array(
                'errors' => false,
                'message' => 'success',
                //'message' => $datalayer_flow,
                'data' => $items
            );
        }
    
    } catch (Exception $e) {

        $response = array(
            'errors' => true,
            'message' => $e->getMessage()
        );

    }

    $resultJson = $this->_resultJsonFactory->create();
    return $resultJson->setData($response);
}

custom.phtml:

$.ajax({
            url: url.build('/customgtm/ajax/datalayer'),
            type: 'POST',
            data: {event : 'productClick', product : productId, position : position, list : listresult},
            dataType: 'json',
            success: function (response) {

                if( !response.errors ) {

                    dataLayer.push({ecommerce:null});
                    dataLayer.push({
                        'event': 'productClick',
                        'ecommerce': {
                            'click': {
                                'actionField': {'list': listresult},
                                'products': [response.data]
                            }
                        }
                    });
                }

            },
            error: function(error) {
                console.log(error);
            }
        });

    });