This is what I meant by the 'if' statement should you want to test it. (I don't use Google I use Alexa)
if (subscription == &Lamp1) {
Serial.print(F("Got: "));
Serial.println((char *)Lamp1.lastread);
if ((char *)Lamp1.lastread) == "ON"){
digitalWrite(Relay1, HIGH);
}
if ((char *)Lamp1.lastread) == "OFF"){
digitalWrite(Relay1, LOW);
}