if (isset($_SERVER["HTTP_X_FORWARDED_PROTO"]) && $_SERVER["HTTP_X_FORWARDED_PROTO"] === "https") {
    $_SERVER["HTTPS"] = "on";
    $_SERVER["SERVER_PORT"] = 443;
}
define("FORCE_SSL_ADMIN", true);
/* Это всё, дальше не редактируем. Успехов! */
<br />
<b>Fatal error</b>:  Call to undefined function wp() in <b>/var/www/html/wp-blog-header.php</b> on line <b>14</b><br />