Yes! As a traveler, you are responsible for returning a vehicle with the same level of fuel it had at the start of the trip, that is, when you picked up the keys. This is true whether the vehicle you rent is gas powered or electric.
Be sure to get a receipt that documents your fuel costs and hold on to it for at least five days after the trip ends in case the owner disputes the fact that you’ve refilled the fuel to its pre-trip level. The best way to avoid disputes is to take pre-trip and post-trip photos of the fuel gauge and upload them as part of your check in and checkout process. The combination of your fuel receipt and photographs will fully document that you’ve followed Turo policy.
You can read the fuel policy in its entirety here.