product:price:amount does not display on variable products

Hello,

Thank you for contacting Rank Math for help with your WooCommerce meta tags.

To display the price and amount metatags you will need to customize the following code snippet and add it to your (child) theme functions.php file:

add_action( 'rank_math/head', function() {
    if ( ! is_product() ) {
        return;
    }
    echo '<meta property="product:price:amount" content="22" />';
}, 99 );

You will need to edit the snippet to dynamically pull the correct price depending on your store setup.
You will also need to create a similar snippet for the meta product currency.

Hope that helps. Please let us know if you have questions.