For the Logitech G29 Driving Force steering wheel you need a power supply with the following specifications: - Voltage: 24V - Current: 2.7A - Plug: 5.5 mm outer diameter / 2.5 mm inner diameter (hollow plug)
You can either look for an original Logitech power supply or buy a compatible replacement power supply with the same specifications. Make sure that the polarity is correct (usually plus inside, minus outside).
If you want a specific recommendation, I can help you find a suitable power supply.