Add Google Structured Data availability, priceValidUntil, url in Magento 2.3.2

Question

In my code current availability, priceValidUntil, url is missing. How to add this in below code

/public_html/vendor/magento/module-catalog/view/base/templates/product/price/amount/default.phtml

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

// @codingStandardsIgnoreFile

?>

<?php /** @var \Magento\Framework\Pricing\Render\Amount $block */ ?>

<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 */ $block->getDisplayLabel() ?></span>
    <?php endif; ?>
    <span <?php if ($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>

Answer 1

I've got availabilty and sku working. Haven't got priceValidUntil yet but when I do I'll update my answer

Add this after <?php if ($block->getSchema()): ?>

<meta itemprop="availability" content="<?php echo $block->getSaleableItem()->isSaleable() ? 'InStock' : 'OutOfStock'; ?>" />
<meta itemprop="url" content="<?= $block->escapeHtmlAttr($block->getSaleableItem()->getProductUrl()); ?>" />

Answer 2

<meta itemprop="priceValidUntil" content="<?= $block->getSaleableItem()->getSpecialToDate(); ?>" />