How to Get Post Meta in .Js File [duplicate]

Javascript cannot directly call PHP functions…

We need JS as well as PHP

JS will send ajax request as soon as document is ready, you need to specify postid yourself..

jQuery(document).ready(function(){
    jQuery.ajax({
        url : "/wp-admin/admin-ajax.php",
        type: "POST",
        data: {'action': 'PriceAJAX', 'postid': 12345},
        success: function(response) {
            Price = response['Theme'];
    });
});

Once it is done, the PHP will kick in, and find the post meta for your specified ID…

function PriceAJAX(){
    $ID = $_POST['postid']
    $Price = get_post_meta($ID, 'product_price', true);
    
    $Data  = array('Price' => $Price);
    wp_send_json($Data);
    wp_die();
}
add_action( 'wp_ajax_nopriv_PriceAJAX', 'PriceAJAX');
add_action( 'wp_ajax_PriceAJAX', 'PriceAJAX' );