Do not use external components.
Module ESP-01 + resistor and capacitor:
https://www.youtube.com/watch?v=XIneZEfahmQ
GPIO3 (RXD) - Output PWM/Sigma-Delta Sound
MP3-decodec uses IRAM Buffer > 20 Kbytes
Support all ESP2866 modules (0.5..16 Mbytes flash)
Set connect AP in playerconfig.h:
define AP_NAME "HOMEAP"
define AP_PASS "01234567890"
The base code is at the official Espressif Github