@Tully Do you already have an antenna which you need to connect with proper wiring? If so then follow the advice from TLS Guy. If not and your local radio stations have a strong signal, you would be surprised how well a single piece of stranded wire will work. A very light gauge of stranded wire is all that is required. Car aerials are typically 31 inches long, so cut a piece of thin insulated stranded wire to 31" (79cm), strip off 3/8" (1cm) of insulation from one end and connect under one of the balanced FM terminals. That's all it takes for basic FM reception.
If you are connecting an external FM antenna, then you will need the proper 2 wire cable, either 75 ohm coax or 300 ohm flat cable. Simple dipole antennas can be purchased on Amazon.