<?php
global $post;
$id = $post->ID;
$url = get_bloginfo('url').'/wp-content/themes/hello-elementor-child/custom/quotes.php?file=invoice&product_id='.$id;
?>
<a class="button demo_button buy_now_button download_btn" href="javascript:void(0)" onclick="downloadquote()"><i class="fa fa-download" aria-hidden="true"></i> Standard Quote  </a>
<script>
    function downloadquote(){
        // Creating element to download pdf 
        var element = document.createElement('a'); 
        var quantity = document.getElementsByClassName("qty")[0];
        var qty = quantity.value;
        var duration = document.getElementsByClassName('wcrp-rental-products-total-days')[0];
        var dur_days = duration.innerText;
        var days = dur_days.replace(/days/g,'');
        if(days == ''){
            alert("Please Select Rental Dates");
            return false;
        }
        
        // Setting the path to the pdf file 
        element.href = '<?php echo $url;?>'+'&quantity='+qty+'&duration='+days; 

        // Name to display as download 
        //element.download = 'GFG.pdf'; 
  
        element.target = '_blank';

        // Adding element to the body 
        document.documentElement.appendChild(element); 

        // Above code is equivalent to 
        // <a href="path to file" download="download name"/> 

        // Trigger the file download 
        element.click();
    }
</script>