Press the 0 button to play file T0.wav, press the 1 button to play file T1.wav, etc. The web interface is identical the related project SFX-web-trigger. The other project uses a much more expensive MP3/OGG decoder board. This project uses a $6 I2S DAC with 3W audio amplifier board. The WAV audio files are stored in the ESP8266 Flash. Most ESP-12s boards and modules come with 4 Mbytes of Flash of which 3 MBbytes is used as a Flash file system named SPIFFS. To store the WAV files in the SPIFFS file system, create a data directory in the same directory with the .INO file. Copy WAV files to the directory with names T0.wav, T1.wav, ... T9.wav. Install the SPIFFS upload tool. Use the tool to upload the WAV files to the ESP8266 Flash.