How to Access Antenna Input on Your Panasonic Fire TV
After connecting an antenna and completing the channel auto scan, you can access the Antenna input by selecting the Input icon on the Home screen. Scroll to "Antenna" and press the select button on your remote to enter.
Once selected, the current station your antenna is tuned to will appear on the screen.
You can also access the station guide by pressing the "Guide" button on your remote. Once selected, a list of all saved channels will appear. The content displayed is provided by the station. If any content is missing, it means it’s currently unavailable from that channel source.
Reference: How to Connect an HD Digital Antenna to Your Panasonic Fire TV.