Add custom attributes and set final price 0 in an if statement under price/amount/default.phtml

[intheshallow]

I am trying to do this globally, and not have to work with this in multiple areas that shows the price. This is the current code I have:

<?php
	$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
	$storeInformation = $objectManager->create('Magento\Store\Model\Information');
	$store = $objectManager->create('Magento\Store\Model\Store');
	$storeInfo = $storeInformation->getStoreInformationObject($store);
	$myBlock = $objectManager->get('Freshley\GetProduct\Block\CurrentProduct');
	$product = $myBlock->getCurrentProduct();
?>

<?php if($product->getData('show_price')): ?>
	<?php if($product->getPriceInfo()->getPrice('final_price')->getValue() == 0): ?>
		<span class="price-call"><a href="tel:+1<?php echo $storeInfo->getPhone(); ?>">Call for Price!</a></span>
	<?php else: ?>
		<span class="price-container <?= /* @escapeNotVerified */ $block->getAdjustmentCssClasses() ?>"
		        <?= $block->getSchema() ? ' itemprop="offers" itemscope itemtype="http://schema.org/Offer"' : '' ?>>
		    <?php if ($block->getDisplayLabel()): ?>
		        <span class="price-label"><?= /* @escapeNotVerified */ $block->getDisplayLabel() ?></span>
		    <?php endif; ?>
			<?php if($product->getData('priced_starting_at')): ?>
				<div class="price-starting-at">Starting at:</div>
			<?php else: ?>
				<div class="price-regular">Our Price:</div>	
			<?php endif; ?>
			<span <?php if ($block->getPriceId()): ?> id="<?= /* @escapeNotVerified */ $block->getPriceId() ?>"<?php endif;?>
				<?= ($block->getPriceDisplayLabel()) ? 'data-label="' . $block->getPriceDisplayLabel() . $block->getPriceDisplayInclExclTaxes() . '"' : '' ?>
				data-price-amount="<?= /* @escapeNotVerified */ $block->getDisplayValue() ?>"
				data-price-type="<?= /* @escapeNotVerified */ $block->getPriceType() ?>"
				class="price-wrapper <?= /* @escapeNotVerified */ $block->getPriceWrapperCss() ?>"
			><?= /* @escapeNotVerified */ $block->formatCurrency($block->getDisplayValue(), (bool)$block->getIncludeContainer()) ?></span>
		    <?php if ($block->hasAdjustmentsHtml()): ?>
		        <?= $block->getAdjustmentsHtml() ?>
		    <?php endif; ?>
		    <?php if ($block->getSchema()): ?>
		        <meta itemprop="price" content="<?= /* @escapeNotVerified */ $block->getDisplayValue() ?>" />
		        <meta itemprop="priceCurrency" content="<?= /* @escapeNotVerified */ $block->getDisplayCurrencyCode() ?>" />
		    <?php endif; ?>
		</span>
	<?php endif; ?>
<?php endif; ?>

I also try to extend $block with getCurrentProduct using this code:

<?php
namespace Freshley\GetProduct\Block;
class CurrentProduct extends \Magento\Framework\View\Element\Template
{
    protected $_registry;

    public function __construct(
        \Magento\Backend\Block\Template\Context $context,
        \Magento\Framework\Registry $registry,
        array $data = []
    )
    {
        $this->_registry = $registry;
        parent::__construct($context, $data);
    }
    
    public function _prepareLayout()
    {
        return parent::_prepareLayout();
    }
        
    public function getCurrentProduct()
    {
        return $this->_registry->registry('current_product');
    }
}
?>

This seems to work fine on a Product Detail page, but it isn't on a Product Listing page or anything that shows the Wishlist sidebar. This is the error I am getting:

Fatal error: Uncaught Error: Call to a member function getData() on null in /chroot/home/davidfai/davidfairclough.com/html/app/design/frontend/Freshley/ultimo_child/Magento_Catalog/templates/product/price/amount/default.phtml