This time your are on your own, for better or worse! What we propose is a device that has a button, and the ESP8266 and when the button is pressed an action of If This Than That is triggered.
What about thinking on power saving options we have with ESP8266? For example, when the device is idle (the button is not pressed for a while) we can put the microcontroller in low power usage mode.
Go on! We'll let you search Google on your own to get the idea of what would be if you were doing a project on your own.
Here are some initial searches:
ESP8266 to IFTTT Using Arduino IDE
IFTTTWebHook ESP8266/ESP32 library
How do I send data from IFTTT to ESP8266 module?