#define LED 18
#define BTN 32

void IRAM_ATTR GLED(){
  digitalWrite(LED, !digitalRead(LED));
}

void setup() {
  // initialize the PWM pin as an output
  pinMode(LED,OUTPUT);
  pinMode(BTN,INPUT);
  attachInterrupt(BTN,GLED,RISING);
}

void loop() {
  // do nothing in the loop

  

}