WordPress Site Down

Hello,

I have recently created a wordpress website [ redundant link removed ], which is down now and getting the below errors. Could anyone please help me to fix this issues ?

This page isn’t working is currently unable to handle this request. HTTP ERROR 500
Unable to communicate back with site to check for fatal errors, so the PHP change was reverted. You will need to upload your PHP file change by some other means, such as by using SFTP.
I was attempting to integrate mailchip with wordpress site, while I duplicated codes from mailchip and paste in /wp/admin : Menu/Appearances/Theme editor/header.php under , When I saving I got some error message, then, at that point immediatly I have erased the glued code, which is replicated from mailchip. Again I attempted to save, then, at that point I am getting syntax error and site was down. I think a few keys/charecters are erased from header.php. or deleted closing codes. copied entiere header.php codes here under. Please guide me how to fix this issues.
[Signature removed by moderator per forum guidelines.]

section and everything up until

* * @link https://developer.wordpress.org/themes/basics/template-files/#template-partials * * @package Astra * @since 1.0.0 */ if ( ! defined( 'ABSPATH' ) ) { exit; // Exit if accessed directly. ?> > "> > 'page', 'class' => 'hfeed site', ) ); ?> > astra_header_after();

astra_content_before(); 
?>
<div id="content" class="site-content">
    <div class="ast-container">

• This topic was modified 4 years, 11 months ago by Yui. Reason: signature dropped
• This topic was modified 4 years, 11 months ago by Jan Dembowski.

The page I need help with: [log in to see the link]