TeslaFi uses the option codes from your vehicle provided by the Tesla API to determine what autopilot version you have.
You can view your vehicles option codes in settings->account->advanced.
All Model 3 vehicles are currently providing the same option codes which include references to autopilot hardware 2.5. At this time is not possible for TeslaFi to determine if a Model 3 has version 3 hardware.
Customer support service by UserEcho