An Internet connection is required to connect the Dremel 3D45 printer to the Polar Cloud. And you must connect your Dremel 3D45 printer to a (local, Internet-connected) network via either WiFi or Ethernet to achieve Internet connection.
For details on connecting your printer to a local network, see your Dremel printer documentation.
Or a video walk-through of connecting your Dremel 3D45 printer to your local network may be found at the Polar 3D YouTube channel: Polar Cloud Enabling your Dremel 3D45.