Tesla Model 3 is being criticized since its launch for the absense of traditional key fob - the car may be accessed via the smartphone Bluetooth integration or the plastic key card that has to be attached to the central pillar.
Although, many owners are upset due to the lack of a convential key, that is used for Model S and Model X. The key fob for Model 3 is available for purchase since the end of last week.
However, the Model 3 key does not support Passive Entry functionality - doors won't be unlocked while approaching the car. So far this opportunity is available only with Bluetooth smartphone connection.