WordPress Version: 6.1
/**
* Sends a HTTP header to limit rendering of pages to same origin iframes.
*
* @since 3.1.3
*
* @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
*/
function send_frame_options_header()
{
header('X-Frame-Options: SAMEORIGIN');
}