1) Currently, the preview works only for domains using HTTP, not HTTPS.
2) For WordPress CMS, you must add the following code to your theme’s functions.php file:
add_filter('redirect_canonical', 'disable_redirect_canonical_for_preview', 10, 2);
function disable_redirect_canonical_for_preview($redirect_url, $requested_url) {
// If the "token" parameter is present, assume it's a preview request
if (isset($_GET['token'])) {
return false;
}
return $redirect_url;
}