There is a demo named testMP3 in the "OpenCatEsp32/ModuleTests" file directory. The main function of this demo is to play .mp3 files stored in the SPIFFS file system. Users can choose to play different .mp3 files by inputting 0~6 numbers (.mp3 file index number) in the serial monitor.
Before compiling the demo, please download, install and configure the software environment (Arduino IDE 1.8.*, development board esp32 2.0.*, library ESP8266Audio 1.9.7, partition configuration BiBoard V0).