LoRa E220 and sending data with security

Hello everyone. I am using the "LoRa E220" library. I managed to get two Ebyte LoRa modules to communicate in fixed mode. Since I will be using the modules to open a gate located at a long distance, I was wondering if there is a need to implement some security thing like a rolling code, or if I am already protected in this way. If I ever implement something like this, can you help me figure out how to do it? I'm using the library methods e220ttl.sendFixedMessage(); for the transmitter; while the receiver reads the received data like this:

 if (e220ttl.available() > 0) {
  ResponseContainer rs = e220ttl.receiveMessage();
   if (rs.data == "on") {
    digitalWrite(relay, HIGH);
   } else if (rs.data == "off"){
    digitalWrite(relay, LOW);
   }
 }