Could you please correct the code is_admin()

What is a moderator? A custom user role? If yes, then:

add_action( 'init', 'blockusers_init' );
function blockusers_init() { 
    if ( is_admin() && (!current_user_can( 'administrator' ) || !current_user_can( 'moderator' ) ) && ! ( defined( 'DOING_AJAX' ) && DOING_AJAX ) ) {
        wp_redirect( 'http://madeeasy-online.com/zhile-2/dobavit-obyavlenie/', 302);
        exit;
    }
}