Wordpress Functions for certain page

1. add this on functions.php 

function sv_hide_header_footer_for_page() {

  if( is_page( 2662 ) ) {

echo '<div class="coupon-notice">Thanks for visiting! As a gift, here\'s a coupon code you can use in our shop: <code>20off</code></div>';

}

}

add_action( 'wp', 'sv_hide_header_footer_for_page' );