38-pin development board
Official Espressif documentation:
ESP32-DevKitC V4 user guide →The ESP32 is a dual-core 240MHz microcontroller with built-in WiFi and Bluetooth. The 38-pin dev board breaks all GPIO pins out on two rows of headers.
It includes two 8-bit DAC outputs on GPIO25 and GPIO26 that produce a true analogue voltage - used in the PAM8403 guide to drive audio into the amplifier.