private function connection() {
      $this->apply_config_db();
      try {
         if ( @$_ENV["daniia_connection"] && !$this->id_conn ) {
            $this->id_conn = $_ENV["daniia_connection"];
         }
         elseif ( !$this->id_conn ) {
            $this->id_conn = new \PDO($this->dsn, $this->user, $this->pass);
         }
      } catch (\PDOException $e) {
         die("Error: " . $e->getMessage() . "<br/>");
      }

      $this->get_instance();
      return $this;
   }