What does 'Please connect HFP first' mean?

[JulietteFitz]

The full name of HFP in cars is Hands-free Profile, which is a software that allows Bluetooth devices to control phone functions such as answering, hanging up, rejecting calls, and voice dialing. The HFP car Bluetooth feature is very convenient to use and can effectively reduce safety hazards. Once the phone is connected to the car's Bluetooth, calls can be managed directly through the car's system. Below is an introduction to car Bluetooth: 1. Function: Bluetooth/car phone is designed for driving safety and comfort. Passengers only need a Bluetooth-enabled phone to connect to the car's Bluetooth, enabling them to make and receive calls through the car's system. 2. Features: Automatically recognizes mobile phones without the need for cables or phone holders; users can control the phone without touching it (keeping both hands on the steering wheel) and use voice commands to answer or make calls. Users can communicate via the car's audio system or Bluetooth wireless headsets.