blank page with hook

[Waqas Saeed]

<?php
if (!defined("WHMCS"))
    die("This file cannot be accessed directly");

function facebookPixelCheckOut()
{
$pixelID1 = "843460539109207";
$codepixel = "<script>
!function(f,b,e,v,n,t,s){if(f.fbq)return;n=f.fbq=function(){n.callMethod?
n.callMethod.apply(n,arguments):n.queue.push(arguments)};if(!f._fbq)f._fbq=n;
n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0;
t.src=v;s=b.getElementsByTagName(e)[0];s.parentNode.insertBefore(t,s)}(window,
document,'script','//connect.facebook.net/en_US/fbevents.js');
fbq('init', '".$pixelID1."');
fbq('track', \"InitiateCheckout\");
</script>
<noscript>
<img height=\"1\" width=\"1\" style=\"display:none\"
src=\"https://www.facebook.com/tr?id=".$pixelID1."&ev=InitiateCheckout&noscript=1\" />";
echo $codepixel;
}

//add_hook("ClientAreaPageViewInvoice",1,"facebookPixelCheckOut");
add_hook("AfterShoppingCartCheckout",0,"facebookPixelCheckOut");


?>

Hello.

This conversion works but if user click on the button Check Out, it shows blank page to user, and after user refresh the page it shows the page. What is causing due to hook that it is bringing up the blank page. but no error. 

 

 

[Kian]

AfterShoppingCartCheckout does not support response. You can't echo/return anything. Your echo is breaking the redirect.

[Waqas Saeed]

@Kian thanks buddy, oh! I didn't got the goodie bag . 😞 

Anyways, I'm new to WHMCS code, framwork

What to do here if I want this script to run. Could you help me using my code to run at the point where it can return/echo without interrupting the redirect. the point the customer completes the checkout and receives the unpaid invoice.