I don't understand the audio output of hfp_hf

[kasasu]

https://github.com/espressif/esp-idf/tr ... _bt/hfp_hf

I'm using this example, but I don't know what to connect to what on the GPIO for analog audio input/output.
I'm a beginner and don't even know if PCM and i2s are different, so please tell me what I should buy and what pins I should connect.
Also, even if the sound quality is poor, I would like to output it from the built-in DAC using the ESP32 alone if possible. Is that possible?
thank you
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