OK totally lost here with Blynk2.0 example!

[Blynk_Coeur]

Waiting for a real push button, you can turn the switch into a push button by coding like this :

BLYNK_WRITE(V1) {//reset maxmin button
  int sw = param.asInt();
  // do reset maxmin
  if (sw == 1) {
    Blynk.virtualWrite(V1, 0);
  } else {
    Blynk.virtualWrite(V1, 1);
  }
}