How to Make WPCodeBox2 Full Width by Hiding the WordPress Menu

<?php 

add_action('admin_head', function(){

if( isset( $_GET['page'] ) && $_GET['page'] === 'wpcodebox2' ) {
    
    echo <<<EOD
    <style type="text/css">
        #adminmenuback {
            margin-left: -160px !important;   
        }
        #wpcontent {
            margin-left: 0px !important;
        }
        #adminmenu {
            display: none;
        }
    </style>
EOD;
}
    
});