Error compiling for NodeMCU 0.9 (ESP-12 Module) card

[johnwasser]

@mh0322

#include "WiFi.h"

Perhaps you mean:
#include "ESP8266WiFi.h"

Which ESPAsyncWebServer library are you using and have you tried the library examples for that library? Most of the ESPAsyncWebServer libraries I was able to find are for the ESP32 processor, not ESP8266.