//todo get product object $product 

$objectManager =\Magento\Framework\App\ObjectManager::getInstance();
$helperImport = $objectManager->get('\Magento\Catalog\Helper\Image');

$imageUrl = $helperImport->init($product, 'product_page_image_small')
                ->setImageFile($product->getSmallImage()) // image,small_image,thumbnail
                ->resize(380)
                ->getUrl();
echo $imageUrl;