Funnily enough, there is no key fob on a Model 3. You are supposed to use your phone to unlock your car (using Bluetooth) or a key car (using NFC) in case your phone is dead or you do not wish to couple your phone with the vehicle.

I personally like the idea because I hate carrying my keys with me and a credit card sized car would be much better for me. But I think Tesla should offer to sell normal key fobs for people who which to use those instead.