Resolver "Control-Allow-Origin' header is present on the requested resource" PHP

RECORDATORIO PERSONAL
Debes colocar

header('Access-Control-Allow-Origin: *');

Ejemplo:

public function getLastID(){    header('Access-Control-Allow-Origin: *');    $comando ="SELECT MAX(".self::ID_NOTICIA.") FROM ". self::NOMBRE_TABLA;
    $sentencia = ConexionBD::obtenerInstancia()->obtenerBD()->prepare($comando);
    if ($sentencia->execute()) {        $resultado = $sentencia->fetch();        return $resultado[0];    } else        return null;}